diff --git a/web/src/__tests__/initial-session-loading.test.tsx b/web/src/__tests__/initial-session-loading.test.tsx
new file mode 100644
index 00000000..6f6d39c9
--- /dev/null
+++ b/web/src/__tests__/initial-session-loading.test.tsx
@@ -0,0 +1,115 @@
+import { describe, expect, test } from "bun:test";
+import { Window } from "happy-dom";
+import { act, createElement, useEffect, useState } from "react";
+import { createRoot, type Root } from "react-dom/client";
+import { useInitialSessionLoading } from "../hooks/use-initial-session-loading";
+
+(globalThis as Record<string, unknown>).IS_REACT_ACT_ENVIRONMENT = true;
+
+const win = new Window();
+const globals = globalThis as Record<string, unknown>;
+if (!globals.window) globals.window = win;
+if (!globals.document) globals.document = win.document;
+if (!globals.navigator) globals.navigator = win.navigator;
+
+function createLoadingHarness() {
+  const latest = { value: false };
+
+  function Probe({ isPending }: { isPending: boolean }) {
+    latest.value = useInitialSessionLoading(isPending);
+    return null;
+  }
+
+  const container = win.document.createElement("div");
+  const root: Root = createRoot(container as unknown as HTMLElement);
+
+  return {
+    latest,
+    render(isPending: boolean) {
+      act(() => root.render(createElement(Probe, { isPending })));
+    },
+    unmount() {
+      act(() => root.unmount());
+    },
+  };
+}
+
+describe("useInitialSessionLoading", () => {
+  // 首次 session 请求应阻塞页面，完成后任何后台刷新都不能重新进入全屏 loading
+  test("仅首次 pending 返回 loading", () => {
+    const harness = createLoadingHarness();
+
+    harness.render(true);
+    expect(harness.latest.value).toBe(true);
+
+    harness.render(false);
+    expect(harness.latest.value).toBe(false);
+
+    harness.render(true);
+    expect(harness.latest.value).toBe(false);
+
+    harness.render(false);
+    expect(harness.latest.value).toBe(false);
+    harness.unmount();
+  });
+
+  // 初始已有 session 结果时不应闪现全屏 loading
+  test("初始非 pending 时直接保持页面可见", () => {
+    const harness = createLoadingHarness();
+
+    harness.render(false);
+    expect(harness.latest.value).toBe(false);
+
+    harness.render(true);
+    expect(harness.latest.value).toBe(false);
+    harness.unmount();
+  });
+
+  // 登录页完成首次加载后，聚焦刷新不得卸载子树或清空未提交表单草稿
+  test("后台 pending 周期保留子组件和本地草稿", () => {
+    const latest = {
+      draft: "",
+      setDraft: null as ((value: string) => void) | null,
+      mountCount: 0,
+    };
+
+    function DraftProbe() {
+      const [draft, setDraft] = useState("");
+      latest.draft = draft;
+      latest.setDraft = setDraft;
+
+      useEffect(() => {
+        latest.mountCount += 1;
+      }, []);
+
+      return null;
+    }
+
+    function Boundary({ isPending }: { isPending: boolean }) {
+      const showLoading = useInitialSessionLoading(isPending);
+      return showLoading ? null : createElement(DraftProbe);
+    }
+
+    const container = win.document.createElement("div");
+    const root = createRoot(container as unknown as HTMLElement);
+
+    act(() => root.render(createElement(Boundary, { isPending: true })));
+    expect(latest.mountCount).toBe(0);
+
+    act(() => root.render(createElement(Boundary, { isPending: false })));
+    expect(latest.mountCount).toBe(1);
+
+    act(() => latest.setDraft?.("admin@fenix.com"));
+    expect(latest.draft).toBe("admin@fenix.com");
+
+    act(() => root.render(createElement(Boundary, { isPending: true })));
+    expect(latest.mountCount).toBe(1);
+    expect(latest.draft).toBe("admin@fenix.com");
+
+    act(() => root.render(createElement(Boundary, { isPending: false })));
+    expect(latest.mountCount).toBe(1);
+    expect(latest.draft).toBe("admin@fenix.com");
+
+    act(() => root.unmount());
+  });
+});
diff --git a/web/src/hooks/use-initial-session-loading.ts b/web/src/hooks/use-initial-session-loading.ts
new file mode 100644
index 00000000..c5410402
--- /dev/null
+++ b/web/src/hooks/use-initial-session-loading.ts
@@ -0,0 +1,16 @@
+import { useEffect, useState } from "react";
+
+/**
+ * 仅在 session 首次解析前返回 loading，后台 revalidation 保持现有页面挂载。
+ */
+export function useInitialSessionLoading(isPending: boolean): boolean {
+  const [hasSettled, setHasSettled] = useState(() => !isPending);
+
+  useEffect(() => {
+    if (!isPending) {
+      setHasSettled(true);
+    }
+  }, [isPending]);
+
+  return isPending && !hasSettled;
+}
diff --git a/web/src/routes/__root.tsx b/web/src/routes/__root.tsx
index b3559210..d0ea6bce 100644
--- a/web/src/routes/__root.tsx
+++ b/web/src/routes/__root.tsx
@@ -3,6 +3,7 @@ import { useEffect } from "react";
 import { useTranslation } from "react-i18next";
 import { Toaster } from "sonner";
 import { OrgProvider } from "../contexts/OrgContext";
+import { useInitialSessionLoading } from "../hooks/use-initial-session-loading";
 import { useSession } from "../lib/auth-client";
 import { ThemeProvider } from "../lib/theme";
 
@@ -13,6 +14,7 @@ export const Route = createRootRoute({
 
 function RootComponent() {
   const { data: session, isPending } = useSession();
+  const isInitialSessionLoading = useInitialSessionLoading(isPending);
   const navigate = useNavigate();
   const pathname = useRouterState({ select: (s) => s.location.pathname });
   const { t } = useTranslation("common");
@@ -30,7 +32,7 @@ function RootComponent() {
     }
   }, [session, isPending, pathname, navigate, isAdminPath]);
 
-  if (isPending) {
+  if (isInitialSessionLoading) {
     return (
       <ThemeProvider defaultTheme="light">
         <div className="flex h-screen flex-col items-center justify-center gap-4">