From f14703b0508482f3a0b8bd6d5312f362621dc87a Mon Sep 17 00:00:00 2001
From: yyg-max <175597134+yyg-max@users.noreply.github.com>
Date: Wed, 14 Oct 2026 10:44:48 +0800
Subject: [PATCH] feat: introduce public account authorization and switching

---
 docs/docs.go                                  | 171 ++++++++++++++-
 docs/swagger.json                             | 171 ++++++++++++++-
 docs/swagger.yaml                             | 110 +++++++++-
 frontend/components/common/admin/credit.tsx   |   5 +-
 frontend/components/common/admin/users.tsx    |  88 ++++----
 .../components/common/general/table-data.tsx  |   1 +
 .../public-account/admin-switch-button.tsx    |  93 +++++++++
 .../common/public-account/bind-button.tsx     | 157 ++++++++++++++
 .../common/public-account/switch-button.tsx   | 103 +++++++++
 frontend/components/layout/header.tsx         |   3 +
 frontend/contexts/user-context.tsx            |  25 ++-
 frontend/lib/services/admin/admin.service.ts  |  40 ++++
 frontend/lib/services/admin/types.ts          |  32 ++-
 frontend/lib/services/user/types.ts           |  22 ++
 frontend/lib/services/user/user.service.ts    |  23 +++
 internal/apps/admin/order/logics.go           |   2 +-
 internal/apps/admin/public_account/errs.go    |  24 +++
 internal/apps/admin/public_account/routers.go | 195 ++++++++++++++++++
 internal/apps/admin/task/routers.go           |   2 +-
 internal/apps/admin/user/errs.go              |   2 +-
 internal/apps/admin/user/routers.go           |  20 +-
 internal/apps/dashboard/logic.go              |   2 +-
 internal/apps/dashboard/routers.go            |   2 +-
 internal/apps/leaderboard/logic.go            |   6 +-
 internal/apps/leaderboard/routers.go          |   6 +-
 internal/apps/leaderboard/utils.go            |   2 +-
 internal/apps/oauth/errs.go                   |   1 +
 internal/apps/oauth/logics.go                 |  17 +-
 internal/apps/oauth/middlewares.go            |  19 +-
 internal/apps/oauth/risk.go                   |   4 +-
 internal/apps/oauth/routers.go                |   2 +-
 internal/apps/payment/routers.go              |   6 +-
 internal/apps/payment/utils.go                |   6 +-
 internal/apps/public_account/errs.go          |  24 +++
 internal/apps/public_account/routers.go       | 137 ++++++++++++
 internal/apps/user/tasks.go                   |   6 +-
 internal/db/migrator/migrator.go              |   3 +-
 internal/model/disputes.go                    |   4 +-
 internal/model/merchant_api_keys.go           |   2 +-
 internal/model/order_transfers.go             |   2 +-
 internal/model/orders.go                      |   4 +-
 internal/model/public_account_bindings.go     |  28 +++
 internal/model/red_envelopes.go               |   4 +-
 internal/model/uploads.go                     |   2 +-
 internal/model/users.go                       |  14 +-
 internal/router/router.go                     |   9 +
 internal/service/payment.go                   |  13 +-
 internal/util/custom_types.go                 |   9 +-
 support-files/sql/create_clickhouse.sql       |   8 +-
 49 files changed, 1518 insertions(+), 113 deletions(-)
 create mode 100644 frontend/components/common/public-account/admin-switch-button.tsx
 create mode 100644 frontend/components/common/public-account/bind-button.tsx
 create mode 100644 frontend/components/common/public-account/switch-button.tsx
 create mode 100644 internal/apps/admin/public_account/errs.go
 create mode 100644 internal/apps/admin/public_account/routers.go
 create mode 100644 internal/apps/public_account/errs.go
 create mode 100644 internal/apps/public_account/routers.go
 create mode 100644 internal/model/public_account_bindings.go

diff --git a/docs/docs.go b/docs/docs.go
index cbb8e673..f1aa707f 100644
--- a/docs/docs.go
+++ b/docs/docs.go
@@ -163,6 +163,39 @@ const docTemplate = `{
                 }
             }
         },
+        "/api/v1/admin/public-accounts": {
+            "get": {
+                "produces": [
+                    "application/json"
+                ],
+                "tags": [
+                    "admin"
+                ],
+                "parameters": [
+                    {
+                        "minimum": 1,
+                        "type": "integer",
+                        "name": "page",
+                        "in": "query"
+                    },
+                    {
+                        "maximum": 100,
+                        "minimum": 1,
+                        "type": "integer",
+                        "name": "page_size",
+                        "in": "query"
+                    }
+                ],
+                "responses": {
+                    "200": {
+                        "description": "OK",
+                        "schema": {
+                            "$ref": "#/definitions/util.ResponseAny"
+                        }
+                    }
+                }
+            }
+        },
         "/api/v1/admin/system-configs": {
             "get": {
                 "produces": [
@@ -530,6 +563,43 @@ const docTemplate = `{
                 }
             }
         },
+        "/api/v1/admin/users/{id}/bind-public": {
+            "post": {
+                "produces": [
+                    "application/json"
+                ],
+                "tags": [
+                    "admin"
+                ],
+                "parameters": [
+                    {
+                        "type": "integer",
+                        "format": "int64",
+                        "description": "目标用户ID",
+                        "name": "id",
+                        "in": "path",
+                        "required": true
+                    },
+                    {
+                        "description": "绑定请求",
+                        "name": "request",
+                        "in": "body",
+                        "required": true,
+                        "schema": {
+                            "$ref": "#/definitions/public_account.bindPublicAccountsRequest"
+                        }
+                    }
+                ],
+                "responses": {
+                    "200": {
+                        "description": "OK",
+                        "schema": {
+                            "$ref": "#/definitions/util.ResponseAny"
+                        }
+                    }
+                }
+            }
+        },
         "/api/v1/admin/users/{id}/status": {
             "put": {
                 "produces": [
@@ -566,6 +636,34 @@ const docTemplate = `{
                 }
             }
         },
+        "/api/v1/admin/users/{id}/switch": {
+            "post": {
+                "produces": [
+                    "application/json"
+                ],
+                "tags": [
+                    "admin"
+                ],
+                "parameters": [
+                    {
+                        "type": "integer",
+                        "format": "int64",
+                        "description": "目标账号ID",
+                        "name": "id",
+                        "in": "path",
+                        "required": true
+                    }
+                ],
+                "responses": {
+                    "200": {
+                        "description": "OK",
+                        "schema": {
+                            "$ref": "#/definitions/util.ResponseAny"
+                        }
+                    }
+                }
+            }
+        },
         "/api/v1/config/public": {
             "get": {
                 "consumes": [
@@ -1756,6 +1854,53 @@ const docTemplate = `{
                 }
             }
         },
+        "/api/v1/user/public-accounts": {
+            "get": {
+                "produces": [
+                    "application/json"
+                ],
+                "tags": [
+                    "user"
+                ],
+                "responses": {
+                    "200": {
+                        "description": "OK",
+                        "schema": {
+                            "$ref": "#/definitions/util.ResponseAny"
+                        }
+                    }
+                }
+            }
+        },
+        "/api/v1/user/public-accounts/switch": {
+            "post": {
+                "produces": [
+                    "application/json"
+                ],
+                "tags": [
+                    "user"
+                ],
+                "parameters": [
+                    {
+                        "description": "切换请求",
+                        "name": "request",
+                        "in": "body",
+                        "required": true,
+                        "schema": {
+                            "$ref": "#/definitions/public_account.switchPublicAccountRequest"
+                        }
+                    }
+                ],
+                "responses": {
+                    "200": {
+                        "description": "OK",
+                        "schema": {
+                            "$ref": "#/definitions/util.ResponseAny"
+                        }
+                    }
+                }
+            }
+        },
         "/f/{id}": {
             "get": {
                 "produces": [
@@ -2475,6 +2620,29 @@ const docTemplate = `{
                 }
             }
         },
+        "public_account.bindPublicAccountsRequest": {
+            "type": "object",
+            "properties": {
+                "public_user_ids": {
+                    "type": "array",
+                    "items": {
+                        "type": "integer"
+                    }
+                }
+            }
+        },
+        "public_account.switchPublicAccountRequest": {
+            "type": "object",
+            "required": [
+                "public_user_id"
+            ],
+            "properties": {
+                "public_user_id": {
+                    "type": "string",
+                    "example": "0"
+                }
+            }
+        },
         "redenvelope.ClaimRequest": {
             "type": "object",
             "required": [
@@ -2610,7 +2778,8 @@ const docTemplate = `{
                     "type": "string"
                 },
                 "user_id": {
-                    "type": "integer"
+                    "type": "string",
+                    "example": "0"
                 }
             }
         },
diff --git a/docs/swagger.json b/docs/swagger.json
index 003dc0fb..0c72c9c4 100644
--- a/docs/swagger.json
+++ b/docs/swagger.json
@@ -154,6 +154,39 @@
                 }
             }
         },
+        "/api/v1/admin/public-accounts": {
+            "get": {
+                "produces": [
+                    "application/json"
+                ],
+                "tags": [
+                    "admin"
+                ],
+                "parameters": [
+                    {
+                        "minimum": 1,
+                        "type": "integer",
+                        "name": "page",
+                        "in": "query"
+                    },
+                    {
+                        "maximum": 100,
+                        "minimum": 1,
+                        "type": "integer",
+                        "name": "page_size",
+                        "in": "query"
+                    }
+                ],
+                "responses": {
+                    "200": {
+                        "description": "OK",
+                        "schema": {
+                            "$ref": "#/definitions/util.ResponseAny"
+                        }
+                    }
+                }
+            }
+        },
         "/api/v1/admin/system-configs": {
             "get": {
                 "produces": [
@@ -521,6 +554,43 @@
                 }
             }
         },
+        "/api/v1/admin/users/{id}/bind-public": {
+            "post": {
+                "produces": [
+                    "application/json"
+                ],
+                "tags": [
+                    "admin"
+                ],
+                "parameters": [
+                    {
+                        "type": "integer",
+                        "format": "int64",
+                        "description": "目标用户ID",
+                        "name": "id",
+                        "in": "path",
+                        "required": true
+                    },
+                    {
+                        "description": "绑定请求",
+                        "name": "request",
+                        "in": "body",
+                        "required": true,
+                        "schema": {
+                            "$ref": "#/definitions/public_account.bindPublicAccountsRequest"
+                        }
+                    }
+                ],
+                "responses": {
+                    "200": {
+                        "description": "OK",
+                        "schema": {
+                            "$ref": "#/definitions/util.ResponseAny"
+                        }
+                    }
+                }
+            }
+        },
         "/api/v1/admin/users/{id}/status": {
             "put": {
                 "produces": [
@@ -557,6 +627,34 @@
                 }
             }
         },
+        "/api/v1/admin/users/{id}/switch": {
+            "post": {
+                "produces": [
+                    "application/json"
+                ],
+                "tags": [
+                    "admin"
+                ],
+                "parameters": [
+                    {
+                        "type": "integer",
+                        "format": "int64",
+                        "description": "目标账号ID",
+                        "name": "id",
+                        "in": "path",
+                        "required": true
+                    }
+                ],
+                "responses": {
+                    "200": {
+                        "description": "OK",
+                        "schema": {
+                            "$ref": "#/definitions/util.ResponseAny"
+                        }
+                    }
+                }
+            }
+        },
         "/api/v1/config/public": {
             "get": {
                 "consumes": [
@@ -1747,6 +1845,53 @@
                 }
             }
         },
+        "/api/v1/user/public-accounts": {
+            "get": {
+                "produces": [
+                    "application/json"
+                ],
+                "tags": [
+                    "user"
+                ],
+                "responses": {
+                    "200": {
+                        "description": "OK",
+                        "schema": {
+                            "$ref": "#/definitions/util.ResponseAny"
+                        }
+                    }
+                }
+            }
+        },
+        "/api/v1/user/public-accounts/switch": {
+            "post": {
+                "produces": [
+                    "application/json"
+                ],
+                "tags": [
+                    "user"
+                ],
+                "parameters": [
+                    {
+                        "description": "切换请求",
+                        "name": "request",
+                        "in": "body",
+                        "required": true,
+                        "schema": {
+                            "$ref": "#/definitions/public_account.switchPublicAccountRequest"
+                        }
+                    }
+                ],
+                "responses": {
+                    "200": {
+                        "description": "OK",
+                        "schema": {
+                            "$ref": "#/definitions/util.ResponseAny"
+                        }
+                    }
+                }
+            }
+        },
         "/f/{id}": {
             "get": {
                 "produces": [
@@ -2466,6 +2611,29 @@
                 }
             }
         },
+        "public_account.bindPublicAccountsRequest": {
+            "type": "object",
+            "properties": {
+                "public_user_ids": {
+                    "type": "array",
+                    "items": {
+                        "type": "integer"
+                    }
+                }
+            }
+        },
+        "public_account.switchPublicAccountRequest": {
+            "type": "object",
+            "required": [
+                "public_user_id"
+            ],
+            "properties": {
+                "public_user_id": {
+                    "type": "string",
+                    "example": "0"
+                }
+            }
+        },
         "redenvelope.ClaimRequest": {
             "type": "object",
             "required": [
@@ -2601,7 +2769,8 @@
                     "type": "string"
                 },
                 "user_id": {
-                    "type": "integer"
+                    "type": "string",
+                    "example": "0"
                 }
             }
         },
diff --git a/docs/swagger.yaml b/docs/swagger.yaml
index f42a3d17..94f6d846 100644
--- a/docs/swagger.yaml
+++ b/docs/swagger.yaml
@@ -418,6 +418,21 @@ definitions:
     - recipient_id
     - recipient_username
     type: object
+  public_account.bindPublicAccountsRequest:
+    properties:
+      public_user_ids:
+        items:
+          type: integer
+        type: array
+    type: object
+  public_account.switchPublicAccountRequest:
+    properties:
+      public_user_id:
+        example: "0"
+        type: string
+    required:
+    - public_user_id
+    type: object
   redenvelope.ClaimRequest:
     properties:
       id:
@@ -510,7 +525,8 @@ definitions:
       task_type:
         type: string
       user_id:
-        type: integer
+        example: "0"
+        type: string
     required:
     - task_type
     type: object
@@ -673,6 +689,27 @@ paths:
             $ref: '#/definitions/util.ResponseAny'
       tags:
       - admin
+  /api/v1/admin/public-accounts:
+    get:
+      parameters:
+      - in: query
+        minimum: 1
+        name: page
+        type: integer
+      - in: query
+        maximum: 100
+        minimum: 1
+        name: page_size
+        type: integer
+      produces:
+      - application/json
+      responses:
+        "200":
+          description: OK
+          schema:
+            $ref: '#/definitions/util.ResponseAny'
+      tags:
+      - admin
   /api/v1/admin/system-configs:
     get:
       produces:
@@ -905,6 +942,30 @@ paths:
             $ref: '#/definitions/util.ResponseAny'
       tags:
       - admin
+  /api/v1/admin/users/{id}/bind-public:
+    post:
+      parameters:
+      - description: 目标用户ID
+        format: int64
+        in: path
+        name: id
+        required: true
+        type: integer
+      - description: 绑定请求
+        in: body
+        name: request
+        required: true
+        schema:
+          $ref: '#/definitions/public_account.bindPublicAccountsRequest'
+      produces:
+      - application/json
+      responses:
+        "200":
+          description: OK
+          schema:
+            $ref: '#/definitions/util.ResponseAny'
+      tags:
+      - admin
   /api/v1/admin/users/{id}/status:
     put:
       parameters:
@@ -928,6 +989,24 @@ paths:
             $ref: '#/definitions/util.ResponseAny'
       tags:
       - admin
+  /api/v1/admin/users/{id}/switch:
+    post:
+      parameters:
+      - description: 目标账号ID
+        format: int64
+        in: path
+        name: id
+        required: true
+        type: integer
+      produces:
+      - application/json
+      responses:
+        "200":
+          description: OK
+          schema:
+            $ref: '#/definitions/util.ResponseAny'
+      tags:
+      - admin
   /api/v1/config/public:
     get:
       consumes:
@@ -1681,6 +1760,35 @@ paths:
             $ref: '#/definitions/util.ResponseAny'
       tags:
       - user
+  /api/v1/user/public-accounts:
+    get:
+      produces:
+      - application/json
+      responses:
+        "200":
+          description: OK
+          schema:
+            $ref: '#/definitions/util.ResponseAny'
+      tags:
+      - user
+  /api/v1/user/public-accounts/switch:
+    post:
+      parameters:
+      - description: 切换请求
+        in: body
+        name: request
+        required: true
+        schema:
+          $ref: '#/definitions/public_account.switchPublicAccountRequest'
+      produces:
+      - application/json
+      responses:
+        "200":
+          description: OK
+          schema:
+            $ref: '#/definitions/util.ResponseAny'
+      tags:
+      - user
   /f/{id}:
     get:
       parameters:
diff --git a/frontend/components/common/admin/credit.tsx b/frontend/components/common/admin/credit.tsx
index 8e441f83..9445bc3c 100644
--- a/frontend/components/common/admin/credit.tsx
+++ b/frontend/components/common/admin/credit.tsx
@@ -91,7 +91,6 @@ function PayConfigDetailPanel({
               <Input
                 type="number"
                 step="1"
-                min="0"
                 value={editData.min_score !== undefined ? editData.min_score.toString() : (config?.min_score?.toString() || '')}
                 placeholder={editData.min_score === undefined && !config?.min_score ? '必需' : ''}
                 onChange={(e) => {
@@ -106,9 +105,7 @@ function PayConfigDetailPanel({
                     return
                   }
 
-                  if (numValue >= 0) {
-                    onEditDataChange('min_score', numValue)
-                  }
+                  onEditDataChange('min_score', numValue)
                 }}
                 className="text-xs text-right h-4 w-16 px-0 rounded-none border-none shadow-none focus-visible:ring-0 focus-visible:ring-offset-0 placeholder:text-[12px]"
               />
diff --git a/frontend/components/common/admin/users.tsx b/frontend/components/common/admin/users.tsx
index 478748a0..41ac0a61 100644
--- a/frontend/components/common/admin/users.tsx
+++ b/frontend/components/common/admin/users.tsx
@@ -20,6 +20,9 @@ import { ErrorInline } from "@/components/layout/error"
 import { DropdownMenu, DropdownMenuContent, DropdownMenuItem, DropdownMenuTrigger } from "@/components/ui/dropdown-menu"
 import { cn } from "@/lib/utils"
 import { useAdminUsers } from "@/contexts/admin-users-context"
+import { useUser } from "@/contexts/user-context"
+import { SwitchAccountButton } from "@/components/common/public-account/admin-switch-button"
+import { BindPublicAccountButton } from "@/components/common/public-account/bind-button"
 
 export function UsersManager() {
   const {
@@ -41,6 +44,8 @@ export function UsersManager() {
     updateUserStatus
   } = useAdminUsers()
 
+  const { user: currentUser } = useUser()
+
   const [selectedUser, setSelectedUser] = useState<AdminUser | null>(null)
   const [detailOpen, setDetailOpen] = useState(false)
   const [updatingUserId, setUpdatingUserId] = useState<string | null>(null)
@@ -387,41 +392,54 @@ export function UsersManager() {
                   </TableCell>
                   <TableCell className="sticky right-0 text-center bg-background z-10 py-1" onClick={(e) => e.stopPropagation()}>
                     <div className="flex items-center justify-center gap-0.5">
-                      <TooltipProvider delayDuration={0}>
-                        <Tooltip>
-                          <TooltipTrigger asChild>
-                            <div>
-                              <Switch
-                                checked={user.is_active}
-                                onCheckedChange={() => handleStatusToggle(user)}
-                                disabled={user.is_admin}
-                                className="scale-75 data-[state=checked]:bg-green-600 h-4 w-7"
-                              />
-                            </div>
-                          </TooltipTrigger>
-                          <TooltipContent side="top" className="text-xs">
-                            {user.is_admin ? '管理员账户' : user.is_active ? '禁用账户' : '启用账户'}
-                          </TooltipContent>
-                        </Tooltip>
-                      </TooltipProvider>
-                      <TooltipProvider delayDuration={0}>
-                        <Tooltip>
-                          <TooltipTrigger asChild>
-                            <Button
-                              variant="ghost"
-                              size="icon"
-                              className="h-6 w-6 text-muted-foreground hover:text-foreground"
-                              onClick={() => handleUpdateCredits(user)}
-                              disabled={updatingUserId === user.id}
-                            >
-                              <Loader2 className={cn("size-3", updatingUserId === user.id && "animate-spin")} />
-                            </Button>
-                          </TooltipTrigger>
-                          <TooltipContent side="top" className="text-xs">
-                            更新积分
-                          </TooltipContent>
-                        </Tooltip>
-                      </TooltipProvider>
+                      {!user.is_admin && (
+                        <TooltipProvider delayDuration={0}>
+                          <Tooltip>
+                            <TooltipTrigger asChild>
+                              <div>
+                                <Switch
+                                  checked={user.is_active}
+                                  onCheckedChange={() => handleStatusToggle(user)}
+                                  className="scale-75 data-[state=checked]:bg-green-600 h-4 w-7"
+                                />
+                              </div>
+                            </TooltipTrigger>
+                            <TooltipContent side="top" className="text-xs">
+                              {user.is_active ? '禁用账户' : '启用账户'}
+                            </TooltipContent>
+                          </Tooltip>
+                        </TooltipProvider>
+                      )}
+                      {Number(user.id) >= 0 && (
+                        <TooltipProvider delayDuration={0}>
+                          <Tooltip>
+                            <TooltipTrigger asChild>
+                              <Button
+                                variant="ghost"
+                                size="icon"
+                                className="h-6 w-6 text-muted-foreground hover:text-foreground"
+                                onClick={() => handleUpdateCredits(user)}
+                                disabled={updatingUserId === user.id}
+                              >
+                                <Loader2 className={cn("size-3", updatingUserId === user.id && "animate-spin")} />
+                              </Button>
+                            </TooltipTrigger>
+                            <TooltipContent side="top" className="text-xs">
+                              更新积分
+                            </TooltipContent>
+                          </Tooltip>
+                        </TooltipProvider>
+                      )}
+                      {Number(user.id) > 0 && (
+                        <BindPublicAccountButton
+                          userId={user.id}
+                          boundPublicAccountIds={user.public_account_ids ?? []}
+                          onChanged={() => fetchUsers(true)}
+                        />
+                      )}
+                      {Number(user.id) < 0 && currentUser?.id !== user.id && (
+                        <SwitchAccountButton accountId={user.id} username={user.username} />
+                      )}
                       <TooltipProvider delayDuration={0}>
                         <Tooltip>
                           <TooltipTrigger asChild>
diff --git a/frontend/components/common/general/table-data.tsx b/frontend/components/common/general/table-data.tsx
index adc4f7a5..ad92ff82 100644
--- a/frontend/components/common/general/table-data.tsx
+++ b/frontend/components/common/general/table-data.tsx
@@ -174,6 +174,7 @@ const TransactionTableRow = React.memo(React.forwardRef<HTMLTableRowElement, {
   const { config: publicConfig } = usePublicConfig()
 
   const isDisputeSupported = order.type === 'payment' || order.type === 'online' || order.type === 'receive'
+  // 用户 ID 统一为精确字符串（后端 json:",string"），直接比较即可
   const isCurrentUserPayer = user?.id === order.payer_user_id
   const isCurrentUserPayee = user?.id === order.payee_user_id
   const isDisputing = order.status === 'disputing' && isCurrentUserPayee
diff --git a/frontend/components/common/public-account/admin-switch-button.tsx b/frontend/components/common/public-account/admin-switch-button.tsx
new file mode 100644
index 00000000..6d109387
--- /dev/null
+++ b/frontend/components/common/public-account/admin-switch-button.tsx
@@ -0,0 +1,93 @@
+"use client"
+
+import { useState } from "react"
+
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+  AlertDialogTrigger,
+} from "@/components/ui/alert-dialog"
+import { Button } from "@/components/ui/button"
+import { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from "@/components/ui/tooltip"
+import { AdminService } from "@/lib/services"
+import { Loader2, UserRoundCog } from "lucide-react"
+import { toast } from "sonner"
+
+/**
+ * 切换账号身份入口（仅展示在公共账号行的操作栏）
+ * 
+ * @param accountId - 目标公共账号 ID
+ * @param username - 目标公共账号用户名（用于确认弹窗展示）
+ * 
+ * @remarks
+ * 切换后 session 绑定用户被替换为目标账号，不影响目标账号自身的登录会话，
+ * 只能退出登录后重新登录恢复原账号。
+ */
+export function SwitchAccountButton({ accountId, username }: { accountId: string, username: string }) {
+  const [switching, setSwitching] = useState(false)
+
+  const handleSwitch = async () => {
+    setSwitching(true)
+    try {
+      await AdminService.switchAccount(accountId)
+      // 切换成功后重新加载页面，清除残留数据并以目标账号身份重新加载
+      window.location.reload()
+    } catch (err) {
+      toast.error("切换失败", {
+        description: err instanceof Error ? err.message : "未知错误",
+      })
+      setSwitching(false)
+    }
+  }
+
+  return (
+    <AlertDialog>
+      <TooltipProvider delayDuration={0}>
+        <Tooltip>
+          <TooltipTrigger asChild>
+            <div>
+              <AlertDialogTrigger asChild>
+                <Button
+                  variant="ghost"
+                  size="icon"
+                  className="h-6 w-6 text-muted-foreground hover:text-foreground"
+                  disabled={switching}
+                >
+                  {switching ? (
+                    <Loader2 className="size-3 animate-spin" />
+                  ) : (
+                    <UserRoundCog className="size-3" />
+                  )}
+                </Button>
+              </AlertDialogTrigger>
+            </div>
+          </TooltipTrigger>
+          <TooltipContent side="top" className="text-xs">
+            切换到该公共账号
+          </TooltipContent>
+        </Tooltip>
+      </TooltipProvider>
+      <AlertDialogContent>
+        <AlertDialogHeader>
+          <AlertDialogTitle>确认切换到公共账号？</AlertDialogTitle>
+          <AlertDialogDescription>
+            切换后当前会话身份将变为公共账号 @{username}（ID: {accountId}）
+          </AlertDialogDescription>
+        </AlertDialogHeader>
+        <AlertDialogFooter>
+          <AlertDialogCancel>取消</AlertDialogCancel>
+          <AlertDialogAction onClick={handleSwitch} disabled={switching}>
+            {switching && <Loader2 className="h-4 w-4 animate-spin" />}
+            确认切换
+          </AlertDialogAction>
+        </AlertDialogFooter>
+      </AlertDialogContent>
+    </AlertDialog>
+  )
+}
diff --git a/frontend/components/common/public-account/bind-button.tsx b/frontend/components/common/public-account/bind-button.tsx
new file mode 100644
index 00000000..e234a720
--- /dev/null
+++ b/frontend/components/common/public-account/bind-button.tsx
@@ -0,0 +1,157 @@
+"use client"
+
+import { useEffect, useState } from "react"
+
+import { Button } from "@/components/ui/button"
+import { Checkbox } from "@/components/ui/checkbox"
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+  DialogTrigger,
+} from "@/components/ui/dialog"
+import { Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from "@/components/ui/tooltip"
+import { AdminService } from "@/lib/services"
+import type { PublicAccount } from "@/lib/services/admin/types"
+import { Link2, Loader2 } from "lucide-react"
+import { toast } from "sonner"
+
+/**
+ * 公共账号绑定按钮（展示在用户列表每行的操作栏，仅真实用户）
+ *
+ * @param userId - 目标真实用户 ID
+ * @param boundPublicAccountIds - 当前已绑定的公共账号 ID 列表
+ * @param onChanged - 绑定保存成功后的回调（刷新列表）
+ *
+ * @remarks
+ * 多对多绑定：保存时全量同步（先清空该用户全部绑定再按勾选重建）。
+ */
+export function BindPublicAccountButton({
+  userId,
+  boundPublicAccountIds,
+  onChanged,
+}: {
+  userId: string
+  boundPublicAccountIds: string[]
+  onChanged: () => void
+}) {
+  const [open, setOpen] = useState(false)
+  const [publicAccounts, setPublicAccounts] = useState<PublicAccount[]>([])
+  const [loadingList, setLoadingList] = useState(false)
+  const [selectedIds, setSelectedIds] = useState<string[]>([])
+  const [pending, setPending] = useState(false)
+
+  // 打开对话框时加载公共账号列表并初始化勾选状态
+  useEffect(() => {
+    if (!open) return
+    setLoadingList(true)
+    setSelectedIds(boundPublicAccountIds)
+    AdminService.listPublicAccounts()
+      .then((res) => setPublicAccounts(res.users))
+      .catch((err) => {
+        toast.error("加载公共账号列表失败", {
+          description: err instanceof Error ? err.message : "未知错误",
+        })
+      })
+      .finally(() => setLoadingList(false))
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [open])
+
+  const toggleAccount = (id: string, checked: boolean) => {
+    setSelectedIds((prev) => (checked ? [...prev, id] : prev.filter((item) => item !== id)))
+  }
+
+  const handleSave = async () => {
+    setPending(true)
+    try {
+      await AdminService.bindPublicAccounts(userId, selectedIds)
+      toast.success("已保存公共账号授权")
+      setOpen(false)
+      onChanged()
+    } catch (err) {
+      toast.error("保存失败", {
+        description: err instanceof Error ? err.message : "未知错误",
+      })
+    } finally {
+      setPending(false)
+    }
+  }
+
+  const boundCount = boundPublicAccountIds.length
+
+  return (
+    <Dialog open={open} onOpenChange={setOpen}>
+      <TooltipProvider delayDuration={0}>
+        <Tooltip>
+          <TooltipTrigger asChild>
+            <div className="relative">
+              <DialogTrigger asChild>
+                <Button
+                  variant="ghost"
+                  size="icon"
+                  className={`h-6 w-6 text-muted-foreground hover:text-foreground ${boundCount > 0 ? "text-primary hover:text-primary" : ""}`}
+                >
+                  <Link2 className="size-3" />
+                </Button>
+              </DialogTrigger>
+              {boundCount > 0 && (
+                <span className="absolute -right-0.5 -top-0.5 flex h-3 min-w-3 items-center justify-center rounded-full bg-primary px-0.5 text-[8px] font-medium text-primary-foreground">
+                  {boundCount}
+                </span>
+              )}
+            </div>
+          </TooltipTrigger>
+          <TooltipContent side="top" className="text-xs">
+            {boundCount > 0 ? `已授权 ${boundCount} 个公共账号` : "授权公共账号"}
+          </TooltipContent>
+        </Tooltip>
+      </TooltipProvider>
+      <DialogContent className="sm:max-w-[420px]">
+        <DialogHeader>
+          <DialogTitle>授权公共账号</DialogTitle>
+          <DialogDescription>
+            勾选该用户可切换的公共账号，保存后全量生效。一个公共账号可同时授权给多个用户。
+          </DialogDescription>
+        </DialogHeader>
+
+        <div className="max-h-[320px] overflow-y-auto rounded-md border border-border/60 p-2">
+          {loadingList ? (
+            <div className="flex items-center justify-center py-8 text-sm text-muted-foreground">
+              <Loader2 className="mr-2 h-4 w-4 animate-spin" />
+              加载中...
+            </div>
+          ) : publicAccounts.length === 0 ? (
+            <div className="py-8 text-center text-sm text-muted-foreground">暂无公共账号</div>
+          ) : (
+            publicAccounts.map((account) => (
+              <label
+                key={account.id}
+                className="flex cursor-pointer items-center gap-2 rounded px-2 py-1.5 hover:bg-muted"
+              >
+                <Checkbox
+                  checked={selectedIds.includes(account.id)}
+                  onCheckedChange={(checked) => toggleAccount(account.id, checked === true)}
+                  disabled={pending}
+                />
+                <span className="text-sm">@{account.username}</span>
+                <span className="ml-auto font-mono text-[10px] text-muted-foreground">
+                  ID: {account.id}
+                </span>
+              </label>
+            ))
+          )}
+        </div>
+
+        <DialogFooter>
+          <Button onClick={handleSave} disabled={pending || loadingList}>
+            {pending && <Loader2 className="h-4 w-4 animate-spin" />}
+            保存
+          </Button>
+        </DialogFooter>
+      </DialogContent>
+    </Dialog>
+  )
+}
diff --git a/frontend/components/common/public-account/switch-button.tsx b/frontend/components/common/public-account/switch-button.tsx
new file mode 100644
index 00000000..4b1f041b
--- /dev/null
+++ b/frontend/components/common/public-account/switch-button.tsx
@@ -0,0 +1,103 @@
+"use client"
+
+import { useState } from "react"
+
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+} from "@/components/ui/alert-dialog"
+import { Button } from "@/components/ui/button"
+import {
+  DropdownMenu,
+  DropdownMenuContent,
+  DropdownMenuItem,
+  DropdownMenuTrigger,
+} from "@/components/ui/dropdown-menu"
+import { useUser } from "@/contexts/user-context"
+import type { PublicAccountInfo } from "@/lib/services/user/types"
+import { Loader2, UserRoundCog } from "lucide-react"
+import { toast } from "sonner"
+
+/**
+ * 公共账号切换按钮（展示在顶部 header）
+ *
+ * 仅真实身份且绑定了公共账号时显示：下拉列出所有绑定的公共账号供切换。
+ * 切换后恢复原身份需退出登录后重新登录（与管理端切换一致）。
+ *
+ * @remarks
+ * 切换成功后重新加载页面，以新身份重新加载数据。
+ */
+export function PublicAccountSwitchButton() {
+  const { user, publicAccounts, switchPublicAccount } = useUser()
+  const [pending, setPending] = useState(false)
+  const [switchTarget, setSwitchTarget] = useState<PublicAccountInfo | null>(null)
+
+  const accounts = publicAccounts?.public_accounts ?? []
+  const canSwitch = !!user && Number(user.id) > 0 && accounts.length > 0
+
+  if (!canSwitch) return null
+
+  const handleSwitch = async () => {
+    if (!switchTarget) return
+    setPending(true)
+    try {
+      await switchPublicAccount(switchTarget.id)
+    } catch (err) {
+      toast.error("切换失败", {
+        description: err instanceof Error ? err.message : "未知错误",
+      })
+      setPending(false)
+    }
+    // 成功后 context 内部会刷新页面，无需重置状态
+  }
+
+  return (
+    <>
+      <DropdownMenu>
+        <DropdownMenuTrigger asChild>
+          <Button
+            variant="ghost"
+            size="icon"
+            className="size-9 text-muted-foreground hover:text-foreground"
+            title="切换为公共账号"
+          >
+            <UserRoundCog className="size-[18px]" />
+            <span className="sr-only">切换为公共账号</span>
+          </Button>
+        </DropdownMenuTrigger>
+        <DropdownMenuContent align="end">
+          {accounts.map((account) => (
+            <DropdownMenuItem key={account.id} onClick={() => setSwitchTarget(account)}>
+              <span className="font-mono text-xs text-muted-foreground">{account.id}</span>
+              <span className="ml-2">@{account.username}</span>
+            </DropdownMenuItem>
+          ))}
+        </DropdownMenuContent>
+      </DropdownMenu>
+
+      <AlertDialog open={!!switchTarget} onOpenChange={(open) => !open && setSwitchTarget(null)}>
+        <AlertDialogContent>
+          <AlertDialogHeader>
+            <AlertDialogTitle>切换到公共账号？</AlertDialogTitle>
+            <AlertDialogDescription>
+              切换后当前会话身份将变为公共账号 @{switchTarget?.username}（ID: {switchTarget?.id}）
+            </AlertDialogDescription>
+          </AlertDialogHeader>
+          <AlertDialogFooter>
+            <AlertDialogCancel>取消</AlertDialogCancel>
+            <AlertDialogAction onClick={handleSwitch} disabled={pending}>
+              {pending && <Loader2 className="h-4 w-4 animate-spin" />}
+              确认
+            </AlertDialogAction>
+          </AlertDialogFooter>
+        </AlertDialogContent>
+      </AlertDialog>
+    </>
+  )
+}
diff --git a/frontend/components/layout/header.tsx b/frontend/components/layout/header.tsx
index e8c532e3..819fe5d5 100644
--- a/frontend/components/layout/header.tsx
+++ b/frontend/components/layout/header.tsx
@@ -12,6 +12,7 @@ import { useTheme } from "next-themes"
 import { useRouter } from "next/navigation"
 import { SearchDialog } from "@/components/layout/search-dialog"
 import { Kbd } from "@/components/ui/kbd"
+import { PublicAccountSwitchButton } from "@/components/common/public-account/switch-button"
 
 
 /**
@@ -89,6 +90,7 @@ export function SiteHeader({ isFullWidth = false, onToggleFullWidth }: { isFullW
               <span className="sr-only">搜索</span>
             </Button>
             <BellButton />
+            <PublicAccountSwitchButton />
             <Button variant="ghost" size="icon" className="size-9 text-muted-foreground hover:text-foreground" onClick={() => router.push('/settings')}>
               <Settings className="size-[18px]" />
               <span className="sr-only">设置</span>
@@ -110,6 +112,7 @@ export function SiteHeader({ isFullWidth = false, onToggleFullWidth }: { isFullW
 
           <div className="ml-auto flex items-center gap-1">
             <BellButton />
+            <PublicAccountSwitchButton />
             <Button variant="ghost" size="icon" className="size-9 text-muted-foreground hover:text-foreground" onClick={() => router.push('/settings')}>
               <Settings className="size-[18px]" />
               <span className="sr-only">设置</span>
diff --git a/frontend/contexts/user-context.tsx b/frontend/contexts/user-context.tsx
index d3e9a6b8..f914606e 100644
--- a/frontend/contexts/user-context.tsx
+++ b/frontend/contexts/user-context.tsx
@@ -4,11 +4,13 @@ import { createContext, useContext, useState, useEffect, useRef, useCallback, Re
 
 import services from '@/lib/services'
 import { User, TrustLevel, PayLevel } from '@/lib/services/auth/types'
+import type { PublicAccountsResponse } from '@/lib/services/user/types'
 
 
 /** 用户状态接口 */
 interface UserState {
   user: User | null
+  publicAccounts: PublicAccountsResponse | null
   loading: boolean
   error: string | null
 }
@@ -17,6 +19,7 @@ interface UserState {
 interface UserContextValue extends UserState {
   refetch: () => Promise<void>
   updatePayKey: (payKey: string) => Promise<void>
+  switchPublicAccount: (publicUserId: string) => Promise<void>
   getTrustLevelLabel: (trustLevel: TrustLevel) => string
   getPayLevelLabel: (payLevel: PayLevel) => string
   logout: () => Promise<void>
@@ -59,6 +62,7 @@ const UserContext = createContext<UserContextValue | undefined>(undefined)
 export function UserProvider({ children }: { children: ReactNode }) {
   const [state, setState] = useState<UserState>({
     user: null,
+    publicAccounts: null,
     loading: true,
     error: null,
   })
@@ -81,14 +85,23 @@ export function UserProvider({ children }: { children: ReactNode }) {
       setState(prev => ({ ...prev, loading: true, error: null }))
       const user = await services.auth.getUserInfo()
 
+      // 公共账号绑定状态（失败不阻断用户信息展示）
+      let publicAccounts: PublicAccountsResponse | null = null
+      try {
+        publicAccounts = await services.user.getPublicAccounts()
+      } catch {
+        // 忽略绑定状态获取失败
+      }
+
       if (!isMountedRef.current) return
 
-      setState({ user, loading: false, error: null })
+      setState({ user, publicAccounts, loading: false, error: null })
     } catch (error) {
       if (!isMountedRef.current) return
 
       setState({
         user: null,
+        publicAccounts: null,
         loading: false,
         error: error instanceof Error ? error.message : '获取用户信息失败',
       })
@@ -106,6 +119,13 @@ export function UserProvider({ children }: { children: ReactNode }) {
     await fetchUser()
   }, [fetchUser])
 
+  /** 切换到已绑定的公共账号身份 */
+  const switchPublicAccount = useCallback(async (publicUserId: string) => {
+    await services.user.switchPublicAccount(publicUserId)
+    // 切换成功后重新加载页面，以公共账号身份重新加载数据
+    window.location.reload()
+  }, [])
+
   /** 用户登出 */
   const logout = useCallback(async () => {
     try {
@@ -113,7 +133,7 @@ export function UserProvider({ children }: { children: ReactNode }) {
 
       if (!isMountedRef.current) return
 
-      setState({ user: null, loading: false, error: null })
+      setState({ user: null, publicAccounts: null, loading: false, error: null })
       window.location.href = '/login'
     } catch (error) {
       if (!isMountedRef.current) {
@@ -145,6 +165,7 @@ export function UserProvider({ children }: { children: ReactNode }) {
         ...state,
         refetch,
         updatePayKey,
+        switchPublicAccount,
         getTrustLevelLabel,
         getPayLevelLabel,
         logout,
diff --git a/frontend/lib/services/admin/admin.service.ts b/frontend/lib/services/admin/admin.service.ts
index ed5904e5..eac5f85b 100644
--- a/frontend/lib/services/admin/admin.service.ts
+++ b/frontend/lib/services/admin/admin.service.ts
@@ -11,6 +11,7 @@ import type {
   DispatchTaskRequest,
   ListUsersRequest,
   ListUsersResponse,
+  ListPublicAccountsResponse,
   UpdateUserStatusRequest,
   ListAdminOrdersRequest,
   ListAdminOrdersResponse,
@@ -345,6 +346,15 @@ export class AdminService extends BaseService {
     return this.get<ListUsersResponse>('/users', request as unknown as Record<string, unknown>);
   }
 
+  /**
+   * 获取公共账号列表（负数 ID）
+   * @returns 公共账号列表及总数
+   * @throws {ForbiddenError} 当无管理员权限时
+   */
+  static async listPublicAccounts(): Promise<ListPublicAccountsResponse> {
+    return this.get<ListPublicAccountsResponse>('/public-accounts', { page: 1, page_size: 100 });
+  }
+
   /**
    * 更新用户状态
    * @param id - 用户 ID
@@ -373,6 +383,36 @@ export class AdminService extends BaseService {
     return this.put<void>(`/users/${ id }/status`, request);
   }
 
+  // ==================== 账号切换 ====================
+
+  /**
+   * 切换到公共账号身份（模拟登录）
+   * @param id - 目标公共账号 ID（负数）
+   * @returns void
+   * @throws {UnauthorizedError} 当未登录时
+   * @throws {ForbiddenError} 当无管理员权限时
+   * @throws {NotFoundError} 当目标公共账号不存在或不可用时
+   * 
+   * @remarks
+   * - 切换后 session 绑定用户被替换为目标账号，不影响目标账号自身的登录会话
+   * - 只能退出登录后重新登录恢复原账号
+   */
+  static async switchAccount(id: string): Promise<void> {
+    return this.post<void>(`/users/${ id }/switch`);
+  }
+
+  /**
+   * 设置用户的公共账号授权（全量同步，空数组即清空授权）
+   * @param id - 目标用户 ID
+   * @param publicUserIds - 公共账号 ID 列表（负数）
+   * @returns void
+   * @throws {ForbiddenError} 当无管理员权限时
+   * @throws {NotFoundError} 当公共账号不存在时
+   */
+  static async bindPublicAccounts(id: string, publicUserIds: string[]): Promise<void> {
+    return this.post<void>(`/users/${ id }/bind-public`, { public_user_ids: publicUserIds.map(Number) });
+  }
+
   // ==================== 订单管理 ====================
 
   /**
diff --git a/frontend/lib/services/admin/types.ts b/frontend/lib/services/admin/types.ts
index 8d0ef673..6ffd84cb 100644
--- a/frontend/lib/services/admin/types.ts
+++ b/frontend/lib/services/admin/types.ts
@@ -190,6 +190,8 @@ export interface AdminUser {
   is_active: boolean;
   /** 是否管理员 */
   is_admin: boolean;
+  /** 绑定的公共账号 ID 列表 */
+  public_account_ids: string[];
   /** 最后登录时间 */
   last_login_at: string;
   /** 创建时间 */
@@ -222,6 +224,32 @@ export interface ListUsersResponse {
   total: number;
 }
 
+/**
+ * 公共账号信息（管理端列表）
+ */
+export interface PublicAccount {
+  /** 公共账号 ID */
+  id: string;
+  /** 用户名 */
+  username: string;
+  /** 昵称 */
+  nickname: string;
+  /** 头像 URL */
+  avatar_url: string;
+  /** 是否激活 */
+  is_active: boolean;
+}
+
+/**
+ * 公共账号列表响应
+ */
+export interface ListPublicAccountsResponse {
+  /** 公共账号列表 */
+  users: PublicAccount[];
+  /** 总数 */
+  total: number;
+}
+
 /**
  * 更新用户状态请求参数
  */
@@ -256,8 +284,8 @@ export interface AdminOrder {
   order_name: string;
   merchant_order_no: string | null;
   client_id: string;
-  payer_user_id: number;
-  payee_user_id: number;
+  payer_user_id: string;
+  payee_user_id: string;
   payer_username: string;
   payee_username: string;
   payer_avatar_url?: string;
diff --git a/frontend/lib/services/user/types.ts b/frontend/lib/services/user/types.ts
index 1c626da4..730434cc 100644
--- a/frontend/lib/services/user/types.ts
+++ b/frontend/lib/services/user/types.ts
@@ -6,3 +6,25 @@ export interface UpdatePayKeyRequest {
   pay_key: string;
 }
 
+/**
+ * 公共账号信息
+ */
+export interface PublicAccountInfo {
+  /** 公共账号 ID */
+  id: string;
+  /** 用户名 */
+  username: string;
+  /** 昵称 */
+  nickname: string;
+  /** 头像 URL */
+  avatar_url: string;
+}
+
+/**
+ * 公共账号绑定列表响应
+ */
+export interface PublicAccountsResponse {
+  /** 可切换的公共账号列表（真实身份下有值） */
+  public_accounts: PublicAccountInfo[];
+}
+
diff --git a/frontend/lib/services/user/user.service.ts b/frontend/lib/services/user/user.service.ts
index aeed82de..a774abe6 100644
--- a/frontend/lib/services/user/user.service.ts
+++ b/frontend/lib/services/user/user.service.ts
@@ -1,4 +1,5 @@
 import { BaseService } from '../core/base.service';
+import type { PublicAccountsResponse } from './types';
 
 /**
  * 用户服务
@@ -26,5 +27,27 @@ export class UserService extends BaseService {
   static async updatePayKey(payKey: string): Promise<void> {
     return this.put<void>('/pay-key', { pay_key: payKey });
   }
+
+  /**
+   * 获取当前用户的公共账号绑定状态
+   * @returns 公共账号绑定状态
+   * @throws {UnauthorizedError} 当未登录时
+   */
+  static async getPublicAccounts(): Promise<PublicAccountsResponse> {
+    return this.get<PublicAccountsResponse>('/public-accounts');
+  }
+
+  /**
+   * 切换到已绑定的公共账号身份
+   * @param publicUserId - 目标公共账号 ID
+   * @returns void
+   * @throws {UnauthorizedError} 当未登录时
+   *
+   * @remarks
+   * - 切换后 session 身份变为公共账号，恢复原身份需退出登录后重新登录
+   */
+  static async switchPublicAccount(publicUserId: string): Promise<void> {
+    return this.post<void>('/public-accounts/switch', { public_user_id: publicUserId });
+  }
 }
 
diff --git a/internal/apps/admin/order/logics.go b/internal/apps/admin/order/logics.go
index 54b6123e..831976eb 100644
--- a/internal/apps/admin/order/logics.go
+++ b/internal/apps/admin/order/logics.go
@@ -93,7 +93,7 @@ func listOrders(ctx context.Context, req *listOrdersRequest) (*listOrdersRespons
 }
 
 // refundOrder 执行管理员退款；有争议时更新争议，无争议时只按需追加订单备注。
-func refundOrder(ctx context.Context, id uint64, req *refundOrderRequest, adminUserID uint64) error {
+func refundOrder(ctx context.Context, id uint64, req *refundOrderRequest, adminUserID int64) error {
 	return db.DB(ctx).Transaction(func(tx *gorm.DB) error {
 		var order model.Order
 		if err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).
diff --git a/internal/apps/admin/public_account/errs.go b/internal/apps/admin/public_account/errs.go
new file mode 100644
index 00000000..ebe5dc7b
--- /dev/null
+++ b/internal/apps/admin/public_account/errs.go
@@ -0,0 +1,24 @@
+/*
+Copyright 2025 linux.do
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package public_account
+
+const (
+	invalidTargetAccount  = "无效的目标账号ID"
+	invalidBindRequest    = "无效的绑定请求"
+	bindTargetNotFound    = "目标用户或公共账号不存在"
+	targetAccountNotFound = "目标账号不存在或不可用"
+)
diff --git a/internal/apps/admin/public_account/routers.go b/internal/apps/admin/public_account/routers.go
new file mode 100644
index 00000000..136684eb
--- /dev/null
+++ b/internal/apps/admin/public_account/routers.go
@@ -0,0 +1,195 @@
+/*
+Copyright 2025 linux.do
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package public_account
+
+import (
+	"net/http"
+	"slices"
+	"strconv"
+
+	"github.com/gin-contrib/sessions"
+	"github.com/gin-gonic/gin"
+	"github.com/linux-do/credit/internal/apps/oauth"
+	"github.com/linux-do/credit/internal/db"
+	"github.com/linux-do/credit/internal/model"
+	"github.com/linux-do/credit/internal/util"
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+)
+
+// listPublicAccountsRequest 公共账号列表查询请求
+type listPublicAccountsRequest struct {
+	Page     int `form:"page" binding:"min=1"`
+	PageSize int `form:"page_size" binding:"min=1,max=100"`
+}
+
+// publicAccount 公共账号信息
+type publicAccount struct {
+	ID        int64  `json:"id,string"`
+	Username  string `json:"username"`
+	Nickname  string `json:"nickname"`
+	AvatarUrl string `json:"avatar_url"`
+	IsActive  bool   `json:"is_active"`
+}
+
+// listPublicAccountsResponse 公共账号列表响应
+type listPublicAccountsResponse struct {
+	Users []publicAccount `json:"users"`
+	Total int64           `json:"total"`
+}
+
+// ListPublicAccounts 列出公共账号（负数 ID）
+// @Tags admin
+// @Produce json
+// @Param request query listPublicAccountsRequest true "查询参数"
+// @Success 200 {object} util.ResponseAny
+// @Router /api/v1/admin/public-accounts [get]
+func ListPublicAccounts(c *gin.Context) {
+	var req listPublicAccountsRequest
+	if err := c.ShouldBindQuery(&req); err != nil {
+		c.JSON(http.StatusBadRequest, util.Err(err.Error()))
+		return
+	}
+
+	var accounts []publicAccount
+	var total int64
+
+	query := db.DB(c.Request.Context()).Table("users").Where("id < ?", 0)
+
+	if err := query.Count(&total).Error; err != nil {
+		c.JSON(http.StatusInternalServerError, util.Err(err.Error()))
+		return
+	}
+
+	offset := (req.Page - 1) * req.PageSize
+	if err := query.
+		Select("id, username, nickname, avatar_url, is_active").
+		Order("id DESC").
+		Offset(offset).
+		Limit(req.PageSize).
+		Find(&accounts).Error; err != nil {
+		c.JSON(http.StatusInternalServerError, util.Err(err.Error()))
+		return
+	}
+
+	c.JSON(http.StatusOK, util.OK(listPublicAccountsResponse{
+		Users: accounts,
+		Total: total,
+	}))
+}
+
+// bindPublicAccountsRequest 绑定公共账号请求（全量同步，空数组即清空授权）
+type bindPublicAccountsRequest struct {
+	PublicUserIDs []int64 `json:"public_user_ids" binding:"dive,lt=0"`
+}
+
+// BindPublicAccounts 设置用户的公共账号授权（全量同步：先清空再按请求重建；空数组即清空授权）
+// @Tags admin
+// @Produce json
+// @Param id path int64 true "目标用户ID"
+// @Param request body bindPublicAccountsRequest true "绑定请求"
+// @Success 200 {object} util.ResponseAny
+// @Router /api/v1/admin/users/{id}/bind-public [post]
+func BindPublicAccounts(c *gin.Context) {
+	userID, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil || userID <= 0 {
+		c.JSON(http.StatusBadRequest, util.Err(invalidTargetAccount))
+		return
+	}
+
+	// gin 校验：每个元素为负数（dive,lt=0）
+	var req bindPublicAccountsRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, util.Err(invalidBindRequest))
+		return
+	}
+
+	// 排序 + 去重
+	publicIDs := slices.Compact(slices.Sorted(slices.Values(req.PublicUserIDs)))
+
+	var count int64
+	if err := db.DB(c.Request.Context()).Model(&model.User{}).
+		Where("id IN ?", append(slices.Clone(publicIDs), userID)).
+		Count(&count).Error; err != nil {
+		c.JSON(http.StatusInternalServerError, util.Err(err.Error()))
+		return
+	}
+	if count != int64(len(publicIDs)+1) {
+		c.JSON(http.StatusNotFound, util.Err(bindTargetNotFound))
+		return
+	}
+
+	// 删除本次未保留的绑定；插入期望绑定，已存在的由唯一索引跳过
+	if err := db.DB(c.Request.Context()).Transaction(func(tx *gorm.DB) error {
+		query := tx.Where("user_id = ?", userID)
+		if len(publicIDs) > 0 {
+			query = query.Where("public_account_id NOT IN ?", publicIDs)
+		}
+		if err := query.Delete(&model.PublicAccountBinding{}).Error; err != nil {
+			return err
+		}
+
+		if len(publicIDs) == 0 {
+			return nil
+		}
+		bindings := make([]model.PublicAccountBinding, 0, len(publicIDs))
+		for _, id := range publicIDs {
+			bindings = append(bindings, model.PublicAccountBinding{PublicAccountID: id, UserID: userID})
+		}
+		return tx.Clauses(clause.OnConflict{DoNothing: true}).Create(bindings).Error
+	}); err != nil {
+		c.JSON(http.StatusInternalServerError, util.Err(err.Error()))
+		return
+	}
+
+	c.JSON(http.StatusOK, util.OKNil())
+}
+
+// SwitchAccount 管理员切换到公共账号身份
+// @Tags admin
+// @Produce json
+// @Param id path int64 true "目标账号ID"
+// @Success 200 {object} util.ResponseAny
+// @Router /api/v1/admin/users/{id}/switch [post]
+func SwitchAccount(c *gin.Context) {
+	accountID, err := strconv.ParseInt(c.Param("id"), 10, 64)
+	if err != nil {
+		c.JSON(http.StatusBadRequest, util.Err(invalidTargetAccount))
+		return
+	}
+
+	// 查询条件限定 id < 0 且与路径参数一致：非公共账号会命中 NotFound 分支
+	var targetAccount model.User
+	if err := db.DB(c.Request.Context()).Where("id = ? AND id < ? AND is_active = ?", accountID, 0, true).First(&targetAccount).Error; err != nil {
+		if err == gorm.ErrRecordNotFound {
+			c.JSON(http.StatusNotFound, util.Err(targetAccountNotFound))
+			return
+		}
+		c.JSON(http.StatusInternalServerError, util.Err(err.Error()))
+		return
+	}
+
+	session := sessions.Default(c)
+	session.Set(oauth.UserIDKey, targetAccount.ID)
+	session.Set(oauth.UserNameKey, targetAccount.Username)
+	if err := session.Save(); err != nil {
+		c.JSON(http.StatusInternalServerError, util.Err(err.Error()))
+		return
+	}
+
+	c.JSON(http.StatusOK, util.OKNil())
+}
diff --git a/internal/apps/admin/task/routers.go b/internal/apps/admin/task/routers.go
index f3e36975..c9ede1c8 100644
--- a/internal/apps/admin/task/routers.go
+++ b/internal/apps/admin/task/routers.go
@@ -43,7 +43,7 @@ type DispatchTaskRequest struct {
 	TaskType  string     `json:"task_type" binding:"required"`
 	StartTime *time.Time `json:"start_time"`
 	EndTime   *time.Time `json:"end_time"`
-	UserID    *uint64    `json:"user_id"`
+	UserID    *int64     `json:"user_id,string"`
 }
 
 // DispatchTask 下发任务
diff --git a/internal/apps/admin/user/errs.go b/internal/apps/admin/user/errs.go
index acfcaec2..4d98d292 100644
--- a/internal/apps/admin/user/errs.go
+++ b/internal/apps/admin/user/errs.go
@@ -17,7 +17,7 @@ limitations under the License.
 package user
 
 const (
-	userNotFound     = "用户不存在"
 	cannotDisable    = "不能禁用管理员用户"
 	updateUserFailed = "更新用户状态失败"
+	userNotFound     = "用户不存在"
 )
diff --git a/internal/apps/admin/user/routers.go b/internal/apps/admin/user/routers.go
index 25238e52..5959c074 100644
--- a/internal/apps/admin/user/routers.go
+++ b/internal/apps/admin/user/routers.go
@@ -31,14 +31,14 @@ import (
 
 // listUsersRequest 用户列表查询请求
 type listUsersRequest struct {
-	Page     int     `form:"page" binding:"min=1"`
-	PageSize int     `form:"page_size" binding:"min=1,max=100"`
-	UserID   *uint64 `form:"user_id" binding:"omitempty,gt=0"`
-	Username string  `form:"username"`
+	Page     int    `form:"page" binding:"min=1"`
+	PageSize int    `form:"page_size" binding:"min=1,max=100"`
+	UserID   *int64 `form:"user_id"`
+	Username string `form:"username"`
 }
 
 type user struct {
-	ID               uint64           `json:"id"`
+	ID               int64            `json:"id,string"`
 	Username         string           `json:"username"`
 	Nickname         string           `json:"nickname"`
 	AvatarUrl        string           `json:"avatar_url"`
@@ -52,6 +52,8 @@ type user struct {
 	AvailableBalance decimal.Decimal  `json:"available_balance"`
 	IsActive         bool             `json:"is_active"`
 	IsAdmin          bool             `json:"is_admin"`
+	// PublicAccountIDs 该用户绑定的公共账号 ID 列表
+	PublicAccountIDs util.StringArray `json:"public_account_ids"`
 	LastLoginAt      time.Time        `json:"last_login_at"`
 	CreatedAt        time.Time        `json:"created_at"`
 	UpdatedAt        time.Time        `json:"updated_at"`
@@ -101,7 +103,9 @@ func ListUsers(c *gin.Context) {
 		Select("id, username, nickname, avatar_url, trust_level, pay_score, " +
 			"total_receive, total_payment, total_transfer, total_community, " +
 			"community_balance, available_balance, is_active, is_admin, " +
-			"last_login_at, created_at, updated_at").
+			"last_login_at, created_at, updated_at, " +
+			"COALESCE((SELECT array_to_json(array_agg(b.public_account_id::text)) " +
+			"FROM public_account_bindings b WHERE b.user_id = users.id), '[]') AS public_account_ids").
 		Order("id DESC").
 		Offset(offset).
 		Limit(req.PageSize).
@@ -138,8 +142,8 @@ func UpdateUserStatus(c *gin.Context) {
 	id := c.Param("id")
 
 	var targetUser struct {
-		ID      uint64 `gorm:"column:id"`
-		IsAdmin bool   `gorm:"column:is_admin"`
+		ID      int64 `gorm:"column:id"`
+		IsAdmin bool  `gorm:"column:is_admin"`
 	}
 	if err := db.DB(c.Request.Context()).
 		Table("users").
diff --git a/internal/apps/dashboard/logic.go b/internal/apps/dashboard/logic.go
index eb814eb8..6929e754 100644
--- a/internal/apps/dashboard/logic.go
+++ b/internal/apps/dashboard/logic.go
@@ -40,7 +40,7 @@ type dailyAmountResult struct {
 
 // queryDailyAmounts 查询每日金额
 // isIncome: true=收入(payee), false=支出(payer)
-func queryDailyAmounts(ctx context.Context, userID uint64, isIncome bool, startDate, endDate time.Time) (map[string]decimal.Decimal, error) {
+func queryDailyAmounts(ctx context.Context, userID int64, isIncome bool, startDate, endDate time.Time) (map[string]decimal.Decimal, error) {
 	var results []dailyAmountResult
 	var err error
 
diff --git a/internal/apps/dashboard/routers.go b/internal/apps/dashboard/routers.go
index 5ce3d457..93faea12 100644
--- a/internal/apps/dashboard/routers.go
+++ b/internal/apps/dashboard/routers.go
@@ -48,7 +48,7 @@ type TopCustomersRequest struct {
 
 // TopCustomer Top客户项
 type TopCustomer struct {
-	UserID      uint64          `json:"user_id"`
+	UserID      int64           `json:"user_id"`
 	Username    string          `json:"username"`
 	TotalAmount decimal.Decimal `json:"total_amount"`
 	OrderCount  int64           `json:"order_count"`
diff --git a/internal/apps/leaderboard/logic.go b/internal/apps/leaderboard/logic.go
index ba292a82..1a055c65 100644
--- a/internal/apps/leaderboard/logic.go
+++ b/internal/apps/leaderboard/logic.go
@@ -56,7 +56,7 @@ func getList(ctx context.Context, req *ListRequest) (*ListResponse, error) {
 	return response, nil
 }
 
-func getUserRank(ctx context.Context, userID uint64) (*UserRankResponse, error) {
+func getUserRank(ctx context.Context, userID int64) (*UserRankResponse, error) {
 	// 检查缓存
 	cacheKey := fmt.Sprintf("%suser:%d", cacheKeyPrefix, userID)
 	if data, err := db.Redis.Get(ctx, db.PrefixedKey(cacheKey)).Bytes(); err == nil {
@@ -77,8 +77,8 @@ func getUserRank(ctx context.Context, userID uint64) (*UserRankResponse, error)
 	// 即：余额更高，或余额相同但 id 更小
 	var rank int64
 	if err := db.DB(ctx).Model(&model.User{}).
-		Where("is_active = ? AND ((available_balance > ?) OR (available_balance = ? AND id < ?))",
-			true, user.AvailableBalance, user.AvailableBalance, userID).
+		Where("id > ? AND is_active = ? AND ((available_balance > ?) OR (available_balance = ? AND id < ?))",
+			0, true, user.AvailableBalance, user.AvailableBalance, userID).
 		Count(&rank).Error; err != nil {
 		return nil, err
 	}
diff --git a/internal/apps/leaderboard/routers.go b/internal/apps/leaderboard/routers.go
index 63d653ac..54bb6297 100644
--- a/internal/apps/leaderboard/routers.go
+++ b/internal/apps/leaderboard/routers.go
@@ -35,7 +35,7 @@ type ListRequest struct {
 
 // LeaderboardEntry 排行榜条目（rank 由前端根据 offset + index + 1 计算）
 type LeaderboardEntry struct {
-	UserID           uint64          `json:"user_id"`
+	UserID           int64           `json:"user_id"`
 	Username         string          `json:"username"`
 	AvatarURL        string          `json:"avatar_url"`
 	AvailableBalance decimal.Decimal `json:"available_balance"`
@@ -58,7 +58,7 @@ type UserRankResponse struct {
 
 // UserRankInfo 用户排名信息
 type UserRankInfo struct {
-	UserID           uint64          `json:"user_id"`
+	UserID           int64           `json:"user_id"`
 	Rank             int             `json:"rank"`
 	AvailableBalance decimal.Decimal `json:"available_balance"`
 }
@@ -118,7 +118,7 @@ func GetMyRank(c *gin.Context) {
 // @Router /api/v1/leaderboard/users/{id} [get]
 func GetUserRankByID(c *gin.Context) {
 	userIDStr := c.Param("id")
-	userID, err := strconv.ParseUint(userIDStr, 10, 64)
+	userID, err := strconv.ParseInt(userIDStr, 10, 64)
 	if err != nil {
 		c.JSON(http.StatusBadRequest, util.Err("invalid user id"))
 		return
diff --git a/internal/apps/leaderboard/utils.go b/internal/apps/leaderboard/utils.go
index 541fb34e..d9215594 100644
--- a/internal/apps/leaderboard/utils.go
+++ b/internal/apps/leaderboard/utils.go
@@ -35,7 +35,7 @@ func getCacheTTL(ctx context.Context) time.Duration {
 func queryLeaderboard(ctx context.Context, req *ListRequest) ([]LeaderboardEntry, int64, error) {
 	offset := (req.Page - 1) * req.PageSize
 
-	baseQuery := db.DB(ctx).Model(&model.User{}).Where("is_active = ?", true)
+	baseQuery := db.DB(ctx).Model(&model.User{}).Where("id > ? AND is_active = ?", 0, true)
 
 	var total int64
 	if err := baseQuery.Count(&total).Error; err != nil {
diff --git a/internal/apps/oauth/errs.go b/internal/apps/oauth/errs.go
index 0414ef7b..dea7e0fe 100644
--- a/internal/apps/oauth/errs.go
+++ b/internal/apps/oauth/errs.go
@@ -20,4 +20,5 @@ const (
 	InvalidState        = "非法登录请求"
 	IDTokenVerifyFailed = "ID Token 验证失败"
 	NonceMismatch       = "nonce 不匹配，可能存在重放攻击"
+	InvalidOAuthUserID  = "OAuth 用户 ID 非法"
 )
diff --git a/internal/apps/oauth/logics.go b/internal/apps/oauth/logics.go
index b2e6030e..378314d4 100644
--- a/internal/apps/oauth/logics.go
+++ b/internal/apps/oauth/logics.go
@@ -35,15 +35,15 @@ import (
 	"gorm.io/gorm"
 )
 
-func GetUserIDFromSession(s sessions.Session) uint64 {
-	userID, ok := s.Get(UserIDKey).(uint64)
+func GetUserIDFromSession(s sessions.Session) int64 {
+	userID, ok := s.Get(UserIDKey).(int64)
 	if !ok {
 		return 0
 	}
 	return userID
 }
 
-func GetUserIDFromContext(c *gin.Context) uint64 {
+func GetUserIDFromContext(c *gin.Context) int64 {
 	session := sessions.Default(c)
 	return GetUserIDFromSession(session)
 }
@@ -101,6 +101,13 @@ func doOAuth(ctx context.Context, code string, nonce string) (*model.User, error
 		}
 	}
 
+	// 负数 ID 为系统保留区间（公共账号），外部 OAuth 流程不允许产生
+	if userInfo.GetID() < 0 {
+		err = errors.New(InvalidOAuthUserID)
+		span.SetStatus(codes.Error, err.Error())
+		return nil, err
+	}
+
 	if !userInfo.Active {
 		err = errors.New(common.BannedAccount)
 		span.SetStatus(codes.Error, err.Error())
@@ -111,6 +118,10 @@ func doOAuth(ctx context.Context, code string, nonce string) (*model.User, error
 	err = db.DB(ctx).Transaction(func(tx *gorm.DB) error {
 		var holder model.User
 		if conflictErr := tx.Where("username = ? AND id != ?", userInfo.Username, userInfo.GetID()).First(&holder).Error; conflictErr == nil {
+			// 负数 ID 均为公共账号，用户名由系统控制，不允许被释放
+			if holder.ID < 0 {
+				return fmt.Errorf("用户名 %s 已被公共账号占用", holder.Username)
+			}
 			// 用户名来自 OAuth 且可能被改名复用；冲突时只释放旧用户名，不禁用原账号。
 			newUsername := fmt.Sprintf("__released_username__:%d:%s", holder.ID, uuid.NewString())
 			if updateErr := tx.Model(&holder).Update("username", newUsername).Error; updateErr != nil {
diff --git a/internal/apps/oauth/middlewares.go b/internal/apps/oauth/middlewares.go
index 9985ac80..a68691e9 100644
--- a/internal/apps/oauth/middlewares.go
+++ b/internal/apps/oauth/middlewares.go
@@ -17,6 +17,7 @@ limitations under the License.
 package oauth
 
 import (
+	"errors"
 	"net/http"
 
 	"github.com/gin-gonic/gin"
@@ -26,10 +27,11 @@ import (
 	"github.com/linux-do/credit/internal/model"
 	"github.com/linux-do/credit/internal/otel_trace"
 	"github.com/linux-do/credit/internal/util"
+	"gorm.io/gorm"
 )
 
 type loginRequiredAuditLog struct {
-	UserID     uint64 `json:"user_id"`
+	UserID     int64  `json:"user_id"`
 	Username   string `json:"username"`
 	ClientIP   string `json:"client_ip"`
 	Method     string `json:"method"`
@@ -47,7 +49,7 @@ func LoginRequired() gin.HandlerFunc {
 
 		// load user
 		userId := GetUserIDFromContext(c)
-		if userId <= 0 {
+		if userId == 0 {
 			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error_msg": common.UnAuthorized, "data": nil})
 			return
 		}
@@ -56,6 +58,10 @@ func LoginRequired() gin.HandlerFunc {
 		var user model.User
 		tx := db.DB(ctx).Where("id = ? AND is_active = ?", userId, true).First(&user)
 		if tx.Error != nil {
+			if errors.Is(tx.Error, gorm.ErrRecordNotFound) {
+				c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error_msg": common.UnAuthorized, "data": nil})
+				return
+			}
 			c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"error_msg": tx.Error.Error(), "data": nil})
 			return
 		}
@@ -71,9 +77,12 @@ func LoginRequired() gin.HandlerFunc {
 		// set user info
 		util.SetToContext(c, UserObjKey, &user)
 
-		if risk, ok := checkOpenAPIUserRisk(ctx, user.ID); ok {
-			if blocked := applyOpenAPIUserRisk(c, risk); blocked {
-				return
+		// 负数 ID 的公共账号不参与 OpenAPI 风险检查
+		if user.ID > 0 {
+			if risk, ok := checkOpenAPIUserRisk(ctx, user.ID); ok {
+				if blocked := applyOpenAPIUserRisk(c, risk); blocked {
+					return
+				}
 			}
 		}
 
diff --git a/internal/apps/oauth/risk.go b/internal/apps/oauth/risk.go
index 5358a151..f7209a17 100644
--- a/internal/apps/oauth/risk.go
+++ b/internal/apps/oauth/risk.go
@@ -65,7 +65,7 @@ type riskBlockDetails struct {
 	Risks      []openAPIUserRiskItem `json:"risks"`
 }
 
-func checkOpenAPIUserRisk(ctx context.Context, userID uint64) (*openAPIUserRiskResponse, bool) {
+func checkOpenAPIUserRisk(ctx context.Context, userID int64) (*openAPIUserRiskResponse, bool) {
 	cfg := config.Config.OpenAPIRisk
 	if !cfg.Enabled || strings.TrimSpace(cfg.BaseURL) == "" {
 		return nil, false
@@ -98,7 +98,7 @@ func checkOpenAPIUserRisk(ctx context.Context, userID uint64) (*openAPIUserRiskR
 	return risk, true
 }
 
-func fetchOpenAPIUserRisk(ctx context.Context, userID uint64) (*openAPIUserRiskResponse, error) {
+func fetchOpenAPIUserRisk(ctx context.Context, userID int64) (*openAPIUserRiskResponse, error) {
 	cfg := config.Config.OpenAPIRisk
 	endpoint := fmt.Sprintf(
 		"%s/api/open/v1/risk/users/%d",
diff --git a/internal/apps/oauth/routers.go b/internal/apps/oauth/routers.go
index 44e71e48..59801b83 100644
--- a/internal/apps/oauth/routers.go
+++ b/internal/apps/oauth/routers.go
@@ -109,7 +109,7 @@ func Callback(c *gin.Context) {
 }
 
 type BasicUserInfo struct {
-	ID               uint64           `json:"id"`
+	ID               int64            `json:"id,string"`
 	Username         string           `json:"username"`
 	Nickname         string           `json:"nickname"`
 	TrustLevel       model.TrustLevel `json:"trust_level"`
diff --git a/internal/apps/payment/routers.go b/internal/apps/payment/routers.go
index 32f25b63..f96c2cd0 100644
--- a/internal/apps/payment/routers.go
+++ b/internal/apps/payment/routers.go
@@ -66,7 +66,7 @@ type GetOrderResponse struct {
 
 // TransferRequest 转账请求
 type TransferRequest struct {
-	RecipientID       uint64          `json:"recipient_id,string" binding:"required"`
+	RecipientID       int64           `json:"recipient_id,string" binding:"required"`
 	RecipientUsername string          `json:"recipient_username" binding:"required"`
 	Amount            decimal.Decimal `json:"amount" binding:"required"`
 	PayKey            string          `json:"pay_key" binding:"required,max=6"`
@@ -135,7 +135,7 @@ func CreateMerchantOrder(c *gin.Context) {
 				return err
 			}
 
-			merchantIDStr := strconv.FormatUint(merchantUser.ID, 10)
+			merchantIDStr := strconv.FormatInt(merchantUser.ID, 10)
 			if errSet := db.Redis.Set(c.Request.Context(), db.PrefixedKey(fmt.Sprintf(OrderMerchantIDCacheKeyFormat, encryptString)), merchantIDStr, remainingTTL).Err(); errSet != nil {
 				return fmt.Errorf("failed to set redis key: %w", errSet)
 			}
@@ -298,7 +298,7 @@ func RefundMerchantOrder(c *gin.Context) {
 
 // MerchantDistributeRequest 商户分发请求
 type MerchantDistributeRequest struct {
-	RecipientID       uint64          `json:"user_id" binding:"required"`
+	RecipientID       int64           `json:"user_id" binding:"required"`
 	RecipientUsername string          `json:"username" binding:"required"`
 	Amount            decimal.Decimal `json:"amount" binding:"required"`
 	MerchantOrderNo   *string         `json:"out_trade_no" binding:"omitempty,min=1,max=64"`
diff --git a/internal/apps/payment/utils.go b/internal/apps/payment/utils.go
index 74f0edd1..c59cb5d1 100644
--- a/internal/apps/payment/utils.go
+++ b/internal/apps/payment/utils.go
@@ -72,7 +72,7 @@ type OrderContext struct {
 }
 
 // validateExpectedPayer 校验当前用户是否为订单绑定的预期付款人。
-func validateExpectedPayer(expectedPayerUserID, currentUserID uint64) error {
+func validateExpectedPayer(expectedPayerUserID, currentUserID int64) error {
 	if expectedPayerUserID == 0 || expectedPayerUserID != currentUserID {
 		return errors.New(OrderPayerMismatch)
 	}
@@ -80,7 +80,7 @@ func validateExpectedPayer(expectedPayerUserID, currentUserID uint64) error {
 }
 
 // createOrReuseMerchantOrder 创建商户订单；幂等键冲突时复用原待支付订单。
-func createOrReuseMerchantOrder(tx *gorm.DB, req *CreateOrderRequest, apiKey *model.MerchantAPIKey, merchantUserID uint64, expiresAt time.Time) (*model.Order, error) {
+func createOrReuseMerchantOrder(tx *gorm.DB, req *CreateOrderRequest, apiKey *model.MerchantAPIKey, merchantUserID int64, expiresAt time.Time) (*model.Order, error) {
 	order := model.Order{
 		OrderName:       req.OrderName,
 		ClientID:        apiKey.ClientID,
@@ -149,7 +149,7 @@ func ParseOrderNo(c *gin.Context, orderNo string) (*OrderContext, error) {
 		return nil, errGet
 	}
 
-	merchantID, errParse := strconv.ParseUint(merchantIDStr, 10, 64)
+	merchantID, errParse := strconv.ParseInt(merchantIDStr, 10, 64)
 	if errParse != nil {
 		return nil, errors.New(OrderNoFormatError)
 	}
diff --git a/internal/apps/public_account/errs.go b/internal/apps/public_account/errs.go
new file mode 100644
index 00000000..e260bcfe
--- /dev/null
+++ b/internal/apps/public_account/errs.go
@@ -0,0 +1,24 @@
+/*
+Copyright 2025 linux.do
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package public_account
+
+const (
+	invalidPublicRequest     = "无效的请求参数"
+	publicAccountNotBound    = "未绑定该公共账号"
+	publicAccountUnavailable = "公共账号不可用"
+	switchPublicNotAllowed   = "当前身份不允许此操作"
+)
diff --git a/internal/apps/public_account/routers.go b/internal/apps/public_account/routers.go
new file mode 100644
index 00000000..4b355000
--- /dev/null
+++ b/internal/apps/public_account/routers.go
@@ -0,0 +1,137 @@
+/*
+Copyright 2025 linux.do
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package public_account
+
+import (
+	"net/http"
+
+	"github.com/gin-contrib/sessions"
+	"github.com/gin-gonic/gin"
+	"github.com/linux-do/credit/internal/apps/oauth"
+	"github.com/linux-do/credit/internal/db"
+	"github.com/linux-do/credit/internal/model"
+	"github.com/linux-do/credit/internal/util"
+	"gorm.io/gorm"
+)
+
+// PublicAccountInfo 公共账号信息
+type PublicAccountInfo struct {
+	ID        int64  `json:"id,string"`
+	Username  string `json:"username"`
+	Nickname  string `json:"nickname"`
+	AvatarUrl string `json:"avatar_url"`
+}
+
+// PublicAccountsResponse 公共账号绑定列表响应
+type PublicAccountsResponse struct {
+	// 可切换的公共账号列表（仅真实身份下有值）
+	PublicAccounts []PublicAccountInfo `json:"public_accounts"`
+}
+
+// GetPublicAccounts 获取当前用户绑定的公共账号列表
+// @Tags user
+// @Produce json
+// @Success 200 {object} util.ResponseAny
+// @Router /api/v1/user/public-accounts [get]
+func GetPublicAccounts(c *gin.Context) {
+	currentUser, _ := util.GetFromContext[*model.User](c, oauth.UserObjKey)
+	response := PublicAccountsResponse{}
+
+	// 仅真实身份返回绑定列表；公共账号身份无切换能力（退出重登恢复）
+	if currentUser.ID < 0 {
+		c.JSON(http.StatusOK, util.OK(response))
+		return
+	}
+
+	var accounts []PublicAccountInfo
+	if err := db.DB(c.Request.Context()).
+		Table("public_account_bindings").
+		Select("users.id AS id, users.username AS username, users.nickname AS nickname, users.avatar_url AS avatar_url").
+		Joins("JOIN users ON users.id = public_account_bindings.public_account_id").
+		Where("public_account_bindings.user_id = ?", currentUser.ID).
+		Scan(&accounts).Error; err != nil {
+		c.JSON(http.StatusInternalServerError, util.Err(err.Error()))
+		return
+	}
+	response.PublicAccounts = accounts
+
+	c.JSON(http.StatusOK, util.OK(response))
+}
+
+// switchPublicAccountRequest 切换公共账号请求
+type switchPublicAccountRequest struct {
+	PublicUserID int64 `json:"public_user_id,string" binding:"required"`
+}
+
+// SwitchPublicAccount 切换到已绑定的公共账号身份
+// @Tags user
+// @Produce json
+// @Param request body switchPublicAccountRequest true "切换请求"
+// @Success 200 {object} util.ResponseAny
+// @Router /api/v1/user/public-accounts/switch [post]
+func SwitchPublicAccount(c *gin.Context) {
+	currentUser, _ := util.GetFromContext[*model.User](c, oauth.UserObjKey)
+	if currentUser.ID < 0 {
+		c.JSON(http.StatusBadRequest, util.Err(switchPublicNotAllowed))
+		return
+	}
+
+	var req switchPublicAccountRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, util.Err(invalidPublicRequest))
+		return
+	}
+	if req.PublicUserID >= 0 {
+		c.JSON(http.StatusBadRequest, util.Err(invalidPublicRequest))
+		return
+	}
+
+	tx := db.DB(c.Request.Context())
+
+	// 校验绑定关系存在
+	var binding model.PublicAccountBinding
+	if err := tx.Where("user_id = ? AND public_account_id = ?", currentUser.ID, req.PublicUserID).First(&binding).Error; err != nil {
+		if err == gorm.ErrRecordNotFound {
+			c.JSON(http.StatusBadRequest, util.Err(publicAccountNotBound))
+			return
+		}
+		c.JSON(http.StatusInternalServerError, util.Err(err.Error()))
+		return
+	}
+
+	// 公共账号必须可用
+	var publicAccount model.User
+	if err := tx.Where("id = ? AND is_active = ?", req.PublicUserID, true).First(&publicAccount).Error; err != nil {
+		if err == gorm.ErrRecordNotFound {
+			c.JSON(http.StatusBadRequest, util.Err(publicAccountUnavailable))
+			return
+		}
+		c.JSON(http.StatusInternalServerError, util.Err(err.Error()))
+		return
+	}
+
+	// 切换后 session 身份变为公共账号，恢复原身份需退出重新登录
+	session := sessions.Default(c)
+	session.Set(oauth.UserIDKey, publicAccount.ID)
+	session.Set(oauth.UserNameKey, publicAccount.Username)
+	if err := session.Save(); err != nil {
+		c.JSON(http.StatusInternalServerError, util.Err(err.Error()))
+		return
+	}
+
+	c.JSON(http.StatusOK, util.OKNil())
+}
diff --git a/internal/apps/user/tasks.go b/internal/apps/user/tasks.go
index 66f4e246..990cc354 100644
--- a/internal/apps/user/tasks.go
+++ b/internal/apps/user/tasks.go
@@ -134,8 +134,8 @@ func batchUpdateUserScores(ctx context.Context, userScores []model.LeaderboardUs
 		return nil
 	}
 
-	userIDs := make([]uint64, len(userScores))
-	scoreMap := make(map[uint64]int64, len(userScores))
+	userIDs := make([]int64, len(userScores))
+	scoreMap := make(map[int64]int64, len(userScores))
 	for i, u := range userScores {
 		userIDs[i] = u.ID
 		scoreMap[u.ID] = u.TotalScore
@@ -243,7 +243,7 @@ func batchUpdateUserScores(ctx context.Context, userScores []model.LeaderboardUs
 // HandleUpdateSingleUserGamificationScore 处理用户积分更新任务
 func HandleUpdateSingleUserGamificationScore(ctx context.Context, t *asynq.Task) error {
 	var payload struct {
-		UserID     uint64                  `json:"user_id"`
+		UserID     int64                   `json:"user_id"`
 		UserScores []model.LeaderboardUser `json:"user_scores"`
 	}
 	if err := json.Unmarshal(t.Payload(), &payload); err != nil {
diff --git a/internal/db/migrator/migrator.go b/internal/db/migrator/migrator.go
index 0991c26e..54d6f909 100644
--- a/internal/db/migrator/migrator.go
+++ b/internal/db/migrator/migrator.go
@@ -44,6 +44,7 @@ func Migrate() {
 		&model.RedEnvelope{},
 		&model.RedEnvelopeClaim{},
 		&model.Upload{},
+		&model.PublicAccountBinding{},
 	); err != nil {
 		log.Fatalf("[PostgreSQL] auto migrate failed: %v\n", err)
 	}
@@ -177,7 +178,7 @@ func initUserPayConfigs() {
 	defaultConfigs := []model.UserPayConfig{
 		{
 			Level:          model.PayLevelFree,
-			MinScore:       0,
+			MinScore:       -999999,
 			MaxScore:       int64Ptr(2000),
 			DailyLimit:     int64Ptr(1000),
 			FeeRate:        decimal.Zero,
diff --git a/internal/model/disputes.go b/internal/model/disputes.go
index 0da32ed8..38a11c41 100644
--- a/internal/model/disputes.go
+++ b/internal/model/disputes.go
@@ -34,10 +34,10 @@ const (
 type Dispute struct {
 	ID                uint64        `json:"id,string" gorm:"primaryKey"`
 	OrderID           uint64        `json:"order_id,string" gorm:"uniqueIndex:idx_dispute_order;index:idx_dispute_order_status,priority:1;not null"`
-	InitiatorUserID   uint64        `json:"initiator_user_id" gorm:"not null;index:idx_initiator_status_created,priority:1"`
+	InitiatorUserID   int64         `json:"initiator_user_id" gorm:"not null;index:idx_initiator_status_created,priority:1"`
 	Reason            string        `json:"reason" gorm:"size:500;not null"`
 	Status            DisputeStatus `json:"status" gorm:"type:varchar(20);index;index:idx_dispute_order_status,priority:2;index:idx_initiator_status_created,priority:2;not null;default:'disputing'"`
-	HandlerUserID     *uint64       `json:"handler_user_id" gorm:"index"`
+	HandlerUserID     *int64        `json:"handler_user_id" gorm:"index"`
 	InitiatorUsername string        `json:"initiator_username" gorm:"-:migration;->"`
 	HandlerUsername   string        `json:"handler_username" gorm:"-:migration;->"`
 	CreatedAt         time.Time     `json:"created_at" gorm:"autoCreateTime;index:idx_initiator_status_created,priority:3"`
diff --git a/internal/model/merchant_api_keys.go b/internal/model/merchant_api_keys.go
index f54406af..3ab3da22 100644
--- a/internal/model/merchant_api_keys.go
+++ b/internal/model/merchant_api_keys.go
@@ -25,7 +25,7 @@ import (
 
 type MerchantAPIKey struct {
 	ID             uint64         `json:"id,string" gorm:"primaryKey"`
-	UserID         uint64         `json:"user_id" gorm:"not null;index:idx_merchant_api_keys_user_created,priority:1"`
+	UserID         int64          `json:"user_id" gorm:"not null;index:idx_merchant_api_keys_user_created,priority:1"`
 	ClientID       string         `json:"client_id" gorm:"size:64;uniqueIndex;index:idx_client_credentials,priority:2;not null"`
 	ClientSecret   string         `json:"client_secret" gorm:"size:64;index:idx_client_credentials,priority:1;not null"`
 	AppName        string         `json:"app_name" gorm:"size:20;not null"`
diff --git a/internal/model/order_transfers.go b/internal/model/order_transfers.go
index 08f240b5..3bbc332f 100644
--- a/internal/model/order_transfers.go
+++ b/internal/model/order_transfers.go
@@ -34,7 +34,7 @@ const (
 type OrderTransfer struct {
 	ID          uint64              `json:"id,string" gorm:"primaryKey;autoIncrement"`
 	OrderID     uint64              `json:"order_id,string" gorm:"index;uniqueIndex:uk_order_id;index:idx_order_status,priority:1"`
-	PayeeUserID uint64              `json:"payee_user_id" gorm:"index"`
+	PayeeUserID int64               `json:"payee_user_id" gorm:"index"`
 	Amount      decimal.Decimal     `json:"amount" gorm:"type:numeric(20,2);not null"`
 	Status      OrderTransferStatus `json:"status" gorm:"type:varchar(20);not null;index:idx_status_transfer_at,priority:1;index:idx_order_status,priority:2"`
 	TransferAt  time.Time           `json:"transfer_at" gorm:"not null;index:idx_status_transfer_at,priority:2"`
diff --git a/internal/model/orders.go b/internal/model/orders.go
index 8cd064fc..34be1d65 100644
--- a/internal/model/orders.go
+++ b/internal/model/orders.go
@@ -62,8 +62,8 @@ type Order struct {
 	OrderName       string          `json:"order_name" gorm:"size:64;not null;index"`
 	MerchantOrderNo *string         `json:"merchant_order_no" gorm:"size:64;index:idx_orders_merchant_order_no;uniqueIndex:idx_orders_client_merchant_order,priority:2"`
 	ClientID        string          `json:"client_id" gorm:"size:64;index:idx_orders_client_status_created,priority:1;index:idx_orders_client_payee,priority:1;index:idx_orders_client_payer,priority:1;uniqueIndex:idx_orders_client_merchant_order,priority:1"`
-	PayerUserID     uint64          `json:"payer_user_id" gorm:"index:idx_orders_payer_status_type_created,priority:1;index:idx_orders_payer_status_type_trade,priority:1;index:idx_orders_client_payer,priority:2"`
-	PayeeUserID     uint64          `json:"payee_user_id" gorm:"index:idx_orders_payee_status_type_created,priority:1;index:idx_orders_client_payee,priority:2"`
+	PayerUserID     int64           `json:"payer_user_id,string" gorm:"index:idx_orders_payer_status_type_created,priority:1;index:idx_orders_payer_status_type_trade,priority:1;index:idx_orders_client_payer,priority:2"`
+	PayeeUserID     int64           `json:"payee_user_id,string" gorm:"index:idx_orders_payee_status_type_created,priority:1;index:idx_orders_client_payee,priority:2"`
 	PayerUsername   string          `json:"payer_username" gorm:"-:migration;->"`
 	PayeeUsername   string          `json:"payee_username" gorm:"-:migration;->"`
 	Amount          decimal.Decimal `json:"amount" gorm:"type:numeric(20,2);not null;index"`
diff --git a/internal/model/public_account_bindings.go b/internal/model/public_account_bindings.go
new file mode 100644
index 00000000..28846cd0
--- /dev/null
+++ b/internal/model/public_account_bindings.go
@@ -0,0 +1,28 @@
+/*
+Copyright 2025 linux.do
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package model
+
+import "time"
+
+// PublicAccountBinding 公共账号与真实用户的绑定关系（多对多）
+type PublicAccountBinding struct {
+	ID              uint64    `json:"id,string" gorm:"primaryKey;autoIncrement"`
+	PublicAccountID int64     `json:"public_account_id,string" gorm:"uniqueIndex:uk_binding_pa_user,priority:1;not null"`
+	UserID          int64     `json:"user_id,string" gorm:"uniqueIndex:uk_binding_pa_user,priority:2;index:idx_binding_user_pa,priority:1;not null"`
+	CreatedAt       time.Time `json:"created_at" gorm:"autoCreateTime"`
+	UpdatedAt       time.Time `json:"updated_at" gorm:"autoUpdateTime"`
+}
diff --git a/internal/model/red_envelopes.go b/internal/model/red_envelopes.go
index d6b7d876..5b4faaec 100644
--- a/internal/model/red_envelopes.go
+++ b/internal/model/red_envelopes.go
@@ -40,7 +40,7 @@ const (
 // RedEnvelope 红包
 type RedEnvelope struct {
 	ID                  uint64            `json:"id,string" gorm:"primaryKey"`
-	CreatorID           uint64            `json:"creator_id,string" gorm:"index;not null"`
+	CreatorID           int64             `json:"creator_id,string" gorm:"index;not null"`
 	CreatorUsername     string            `json:"creator_username" gorm:"-:migration;->"`
 	CreatorAvatarURL    string            `json:"creator_avatar_url" gorm:"-:migration;->"`
 	Type                RedEnvelopeType   `json:"type" gorm:"type:varchar(20);not null"`
@@ -61,7 +61,7 @@ type RedEnvelope struct {
 type RedEnvelopeClaim struct {
 	ID            uint64          `json:"id,string" gorm:"primaryKey"`
 	RedEnvelopeID uint64          `json:"red_envelope_id,string" gorm:"uniqueIndex:idx_red_envelope_user,priority:2;not null"`
-	UserID        uint64          `json:"user_id,string" gorm:"uniqueIndex:idx_red_envelope_user,priority:1;not null"`
+	UserID        int64           `json:"user_id,string" gorm:"uniqueIndex:idx_red_envelope_user,priority:1;not null"`
 	Username      string          `json:"username" gorm:"-:migration;->"`
 	AvatarURL     string          `json:"avatar_url" gorm:"-:migration;->"`
 	Amount        decimal.Decimal `json:"amount" gorm:"type:numeric(20,2);not null"`
diff --git a/internal/model/uploads.go b/internal/model/uploads.go
index 206a310d..b04c4002 100644
--- a/internal/model/uploads.go
+++ b/internal/model/uploads.go
@@ -38,7 +38,7 @@ const (
 // Upload 上传文件记录
 type Upload struct {
 	ID        uint64       `json:"id,string" gorm:"primaryKey"`
-	UserID    uint64       `json:"user_id,string" gorm:"index;not null"`
+	UserID    int64        `json:"user_id,string" gorm:"index;not null"`
 	FilePath  string       `json:"file_path" gorm:"size:500;not null;uniqueIndex"` // 文件路径
 	FileSize  int64        `json:"file_size" gorm:"not null"`                      // 文件大小（字节）
 	Type      string       `json:"type" gorm:"column:type;size:50;not null;index"` // 类型 (cover, heterotypic)
diff --git a/internal/model/users.go b/internal/model/users.go
index bec0daa7..2316ed91 100644
--- a/internal/model/users.go
+++ b/internal/model/users.go
@@ -48,7 +48,7 @@ const (
 
 // OAuthUserInfo 用户信息结构（同时支持 OIDC ID Token claims 和 UserEndpoint 响应）
 type OAuthUserInfo struct {
-	Id         uint64     `json:"id"`
+	Id         int64      `json:"id"`
 	Sub        string     `json:"sub"`
 	Username   string     `json:"username"`
 	Name       string     `json:"name"`
@@ -58,13 +58,13 @@ type OAuthUserInfo struct {
 }
 
 // GetID 获取用户 ID
-func (u *OAuthUserInfo) GetID() uint64 {
+func (u *OAuthUserInfo) GetID() int64 {
 	if u.Id != 0 {
 		return u.Id
 	}
 	// 从 sub 解析（OIDC 格式）
 	if u.Sub != "" {
-		if id, err := strconv.ParseUint(u.Sub, 10, 64); err == nil {
+		if id, err := strconv.ParseInt(u.Sub, 10, 64); err == nil {
 			return id
 		}
 	}
@@ -85,13 +85,13 @@ type LeaderboardResponse struct {
 
 // LeaderboardUser 排行榜用户信息
 type LeaderboardUser struct {
-	ID         uint64 `json:"id"`
+	ID         int64  `json:"id"`
 	Username   string `json:"username"`
 	TotalScore int64  `json:"total_score"`
 }
 
 type User struct {
-	ID               uint64          `json:"id" gorm:"primaryKey;index:idx_users_active_bal_id,priority:3"`
+	ID               int64           `json:"id" gorm:"primaryKey;index:idx_users_active_bal_id,priority:3"`
 	Username         string          `json:"username" gorm:"size:255;uniqueIndex"`
 	Nickname         string          `json:"nickname" gorm:"size:255"`
 	AvatarUrl        string          `json:"avatar_url" gorm:"size:255"`
@@ -113,7 +113,7 @@ type User struct {
 	UpdatedAt        time.Time       `json:"updated_at" gorm:"autoUpdateTime;index"`
 }
 
-func (u *User) GetByID(tx *gorm.DB, id uint64) error {
+func (u *User) GetByID(tx *gorm.DB, id int64) error {
 	if err := tx.Where("id = ?", id).First(u).Error; err != nil {
 		return err
 	}
@@ -121,7 +121,7 @@ func (u *User) GetByID(tx *gorm.DB, id uint64) error {
 }
 
 // GetByIDs 批量查询用户
-func GetByIDs(tx *gorm.DB, ids []uint64) ([]User, error) {
+func GetByIDs(tx *gorm.DB, ids []int64) ([]User, error) {
 	var users []User
 	if err := tx.Where("id IN ?", ids).Find(&users).Error; err != nil {
 		return nil, err
diff --git a/internal/router/router.go b/internal/router/router.go
index 6ba5c0af..9568f81d 100644
--- a/internal/router/router.go
+++ b/internal/router/router.go
@@ -29,6 +29,7 @@ import (
 
 	"github.com/linux-do/credit/internal/apps/admin"
 	admin_order "github.com/linux-do/credit/internal/apps/admin/order"
+	admin_public_account "github.com/linux-do/credit/internal/apps/admin/public_account"
 	admin_task "github.com/linux-do/credit/internal/apps/admin/task"
 	admin_user "github.com/linux-do/credit/internal/apps/admin/user"
 	publicconfig "github.com/linux-do/credit/internal/apps/config"
@@ -53,6 +54,7 @@ import (
 	"github.com/linux-do/credit/internal/apps/leaderboard"
 	"github.com/linux-do/credit/internal/apps/oauth"
 	"github.com/linux-do/credit/internal/apps/order"
+	"github.com/linux-do/credit/internal/apps/public_account"
 	"github.com/linux-do/credit/internal/apps/user"
 	"github.com/linux-do/credit/internal/config"
 	"github.com/linux-do/credit/internal/otel_trace"
@@ -143,6 +145,8 @@ func Serve() {
 			userRouter.Use(oauth.LoginRequired())
 			{
 				userRouter.PUT("/pay-key", user.UpdatePayKey)
+				userRouter.GET("/public-accounts", public_account.GetPublicAccounts)
+				userRouter.POST("/public-accounts/switch", public_account.SwitchPublicAccount)
 			}
 
 			// Dashboard
@@ -253,6 +257,11 @@ func Serve() {
 				adminRouter.GET("/users", admin_user.ListUsers)
 				adminRouter.PUT("/users/:id/status", admin_user.UpdateUserStatus)
 
+				// Public accounts
+				adminRouter.GET("/public-accounts", admin_public_account.ListPublicAccounts)
+				adminRouter.POST("/users/:id/bind-public", admin_public_account.BindPublicAccounts)
+				adminRouter.POST("/users/:id/switch", admin_public_account.SwitchAccount)
+
 				// Orders
 				adminRouter.POST("/orders", admin_order.ListOrders)
 				adminRouter.POST("/orders/:id/refund", admin_order.RefundOrder)
diff --git a/internal/service/payment.go b/internal/service/payment.go
index 0b8178e6..9f15a91e 100644
--- a/internal/service/payment.go
+++ b/internal/service/payment.go
@@ -48,7 +48,7 @@ const (
 
 // BalanceUpdateOptions 余额更新选项
 type BalanceUpdateOptions struct {
-	UserID        uint64
+	UserID        int64
 	Amount        decimal.Decimal
 	Operation     BalanceOperation
 	ScoreChange   int64
@@ -97,7 +97,7 @@ func UpdateBalance(tx *gorm.DB, opts BalanceUpdateOptions) error {
 }
 
 // SettlePendingToAvailable 将资金从 PendingBalance 转入 AvailableBalance
-func SettlePendingToAvailable(tx *gorm.DB, userID uint64, amount decimal.Decimal) error {
+func SettlePendingToAvailable(tx *gorm.DB, userID int64, amount decimal.Decimal) error {
 	result := tx.Model(&model.User{}).
 		Where("id = ? AND pending_balance >= ?", userID, amount).
 		UpdateColumns(map[string]interface{}{
@@ -115,14 +115,14 @@ func SettlePendingToAvailable(tx *gorm.DB, userID uint64, amount decimal.Decimal
 
 // CheckDailyLimit 检查用户每日支付限额
 // 返回 nil 表示未超限额，返回 error 表示超限或查询失败
-func CheckDailyLimit(tx *gorm.DB, userID uint64, amount decimal.Decimal, dailyLimit *int64) error {
+func CheckDailyLimit(tx *gorm.DB, userID int64, amount decimal.Decimal, dailyLimit *int64) error {
 	if dailyLimit == nil || *dailyLimit <= 0 {
 		return nil
 	}
 
 	now := time.Now()
 	datePart := int64(now.Year()*10000 + int(now.Month())*100 + now.Day())
-	lockID := int64(userID)*100000000 + datePart
+	lockID := userID*100000000 + datePart
 	if err := tx.Exec("SELECT pg_advisory_xact_lock(?)", lockID).Error; err != nil {
 		return err
 	}
@@ -140,7 +140,7 @@ func CheckDailyLimit(tx *gorm.DB, userID uint64, amount decimal.Decimal, dailyLi
 }
 
 // GetTodayUsedAmount 获取用户当日已使用的支付额度
-func GetTodayUsedAmount(db *gorm.DB, userID uint64) (decimal.Decimal, error) {
+func GetTodayUsedAmount(db *gorm.DB, userID int64) (decimal.Decimal, error) {
 	now := time.Now()
 	todayStart := time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location())
 	todayEnd := todayStart.Add(24 * time.Hour)
@@ -194,6 +194,7 @@ func RefundOrder(tx *gorm.DB, order *model.Order, merchantPayConfig *model.UserP
 		return errors.New(RefundOrderPayerNotFound)
 	}
 
+	// 商家按订单全额退回（手续费由商家承担）
 	merchantScoreDecrease := order.Amount.Mul(merchantPayConfig.ScoreRate).Round(0).IntPart()
 	merchantResult := tx.Model(&model.User{}).
 		Where("id = ?", order.PayeeUserID).
@@ -230,7 +231,7 @@ func RefundOrder(tx *gorm.DB, order *model.Order, merchantPayConfig *model.UserP
 
 // ValidateTestModePayment 验证测试模式下的支付权限
 // 返回 error：nil 表示允许支付，非 nil 表示拒绝支付
-func ValidateTestModePayment(currentUserID, merchantUserID uint64, isTestMode bool) error {
+func ValidateTestModePayment(currentUserID, merchantUserID int64, isTestMode bool) error {
 	if currentUserID == merchantUserID {
 		if !isTestMode {
 			return errors.New(common.CannotPaySelf)
diff --git a/internal/util/custom_types.go b/internal/util/custom_types.go
index aa0ce08d..490c6796 100644
--- a/internal/util/custom_types.go
+++ b/internal/util/custom_types.go
@@ -26,8 +26,13 @@ import (
 type StringArray []string
 
 func (sa *StringArray) Scan(value interface{}) error {
-	bytesValue, ok := value.([]byte)
-	if !ok {
+	var bytesValue []byte
+	switch v := value.(type) {
+	case []byte:
+		bytesValue = v
+	case string:
+		bytesValue = []byte(v)
+	default:
 		return fmt.Errorf("invalid value: %v", value)
 	}
 	return json.Unmarshal(bytesValue, sa)
diff --git a/support-files/sql/create_clickhouse.sql b/support-files/sql/create_clickhouse.sql
index dd0eb9b6..74ac9d30 100644
--- a/support-files/sql/create_clickhouse.sql
+++ b/support-files/sql/create_clickhouse.sql
@@ -2,14 +2,18 @@ CREATE DATABASE IF NOT EXISTS linux_do_credit;
 
 USE linux_do_credit;
 
+-- 注意：payer_user_id / payee_user_id 使用 Int64（支持负数用户 ID，如中央银行账号 id=-1）。
+-- 已有环境升级时需先执行：
+--   ALTER TABLE linux_do_credit.orders MODIFY COLUMN payer_user_id Int64;
+--   ALTER TABLE linux_do_credit.orders MODIFY COLUMN payee_user_id Int64;
 CREATE TABLE IF NOT EXISTS orders
 (
     id                UInt64,
     order_name        String,
     merchant_order_no String,
     client_id         String,
-    payer_user_id     UInt64,
-    payee_user_id     UInt64,
+    payer_user_id     Int64,
+    payee_user_id     Int64,
     amount            Decimal(20, 2),
     status            LowCardinality(String),
     type              LowCardinality(String),