diff --git a/winrandr/__init__.py b/winrandr/__init__.py
index 0e01090..622e47b 100644
--- a/winrandr/__init__.py
+++ b/winrandr/__init__.py
@@ -22,6 +22,7 @@
     "set_auto",
     "set_brightness",
     "set_gamma",
+    "set_night_mode",
     "set_noprimary",
     "set_off",
     "set_position",
@@ -42,6 +43,7 @@
     set_auto,
     set_brightness,
     set_gamma,
+    set_night_mode,
     set_noprimary,
     set_off,
     set_position,
diff --git a/winrandr/api.py b/winrandr/api.py
index 7c6c89f..f4cf308 100644
--- a/winrandr/api.py
+++ b/winrandr/api.py
@@ -4,6 +4,7 @@
     "get_display_props",
     "list_displays",
     "list_providers",
+    "set_night_mode",
     "set_position_relative",
 ]
 
@@ -15,6 +16,7 @@
     identify_display,
     set_brightness,
     set_gamma,
+    set_night_mode,
 )
 from winrandr.features.layout import (  # noqa: F401
     set_noprimary,
diff --git a/winrandr/cli/__init__.py b/winrandr/cli/__init__.py
index c312e28..046de16 100644
--- a/winrandr/cli/__init__.py
+++ b/winrandr/cli/__init__.py
@@ -23,6 +23,7 @@
     _handle_identify,
     _handle_listmodes,
     _handle_mode,
+    _handle_night_mode,
     _handle_off,
     _handle_pos,
     _handle_preferred,
@@ -164,6 +165,8 @@ def _handle_global_ops(args: Namespace) -> None:
         args.output = short
         if args.brightness is not None:
             _handle_brightness(args, t.name)
+        if args.night_mode is not None:
+            _handle_night_mode(args, t.name)
         if args.gamma is not None:
             _handle_gamma(args, t.name)
 
@@ -186,6 +189,8 @@ def _dispatch_display_ops(args: Namespace, device_name: str) -> None:  # noqa: C
         _handle_off(args, device_name)
     if args.brightness is not None:
         _handle_brightness(args, device_name)
+    if args.night_mode is not None:
+        _handle_night_mode(args, device_name)
     if args.reflect:
         _handle_reflect(args, device_name)
     if args.gamma:
@@ -235,7 +240,7 @@ def main() -> None:  # noqa: C901  # 调度型函数，分支复杂度本质
         return
 
     # 全局操作：亮度/伽马可不带 --output，应用到所有已连接显示器
-    _global_only_attrs = frozenset({"brightness", "gamma"})
+    _global_only_attrs = frozenset({"brightness", "gamma", "night_mode"})
     if not args.output:
         mod_attrs = {a for a in _MOD_OP_ATTRS if getattr(args, a, None)}
         if mod_attrs and mod_attrs.issubset(_global_only_attrs):
diff --git a/winrandr/cli/common.py b/winrandr/cli/common.py
index 1353507..a19b9a2 100644
--- a/winrandr/cli/common.py
+++ b/winrandr/cli/common.py
@@ -70,6 +70,7 @@ def _sort_key(n: str) -> tuple[int, int | str]:
     "preferred",
     "off",
     "brightness",
+    "night_mode",
     "reflect",
     "gamma",
     "left_of",
diff --git a/winrandr/cli/handlers.py b/winrandr/cli/handlers.py
index 067fca0..5f5c708 100644
--- a/winrandr/cli/handlers.py
+++ b/winrandr/cli/handlers.py
@@ -9,6 +9,7 @@
     set_auto,
     set_brightness,
     set_gamma,
+    set_night_mode,
     set_off,
     set_position,
     set_position_relative,
@@ -123,6 +124,22 @@ def _handle_brightness(args: Namespace, dn: str) -> None:
     _msg(args, f"已将 {args.output} 亮度设为 {args.brightness}")
 
 
+def _handle_night_mode(args: Namespace, dn: str) -> None:
+    val = args.night_mode
+    if val in ("light", "medium", "heavy"):
+        strength = {"light": 0.2, "medium": 0.5, "heavy": 0.8}[val]
+    else:
+        try:
+            strength = float(val)
+        except (ValueError, TypeError):
+            _fail("--night-mode 参数无效", ["使用 light(20%)/medium(50%)/heavy(80%) 或数值 0.0-1.0"])
+        if not 0.0 <= strength <= 1.0:
+            _fail("夜间模式强度必须在 0.0-1.0 之间")
+    if not args.dry_run and not set_night_mode(dn, strength):
+        _fail("设置夜间模式失败", ["某些驱动或远程桌面环境不支持伽马校正", "使用 --verbose 查看详细日志"])
+    _msg(args, f"已将 {args.output} 的蓝光强度减弱 {int(strength * 100)}%")
+
+
 def _handle_reflect(args: Namespace, dn: str) -> None:
     if args.reflect in ("x", "y"):
         _fail(f"单轴镜像翻转（-{args.reflect}）在 Windows 上无标准 API 支持")
diff --git a/winrandr/cli/parser.py b/winrandr/cli/parser.py
index 8f3a249..796b2d7 100644
--- a/winrandr/cli/parser.py
+++ b/winrandr/cli/parser.py
@@ -63,6 +63,11 @@ def build_parser() -> argparse.ArgumentParser:
 
     g_img = p.add_argument_group("图像调节")
     g_img.add_argument("--brightness", type=float, help="亮度值（0.1-2.0，1.0 为正常）")
+    g_img.add_argument(
+        "--night-mode",
+        metavar="light|medium|heavy|0.0-1.0",
+        help="夜间模式：减少蓝光（预设 light/medium/heavy 或数值）",
+    )
     g_img.add_argument("--gamma", metavar="R:G:B", help="伽马校正（如 1.0:0.9:0.8）")
     g_img.add_argument("--reflect", choices=["normal", "x", "y", "xy"], help="镜像翻转（仅 xy 支持）")
     g_img.add_argument("-x", action="store_true", help=argparse.SUPPRESS)
diff --git a/winrandr/features/gamma.py b/winrandr/features/gamma.py
index 2c9eefa..d51c98b 100644
--- a/winrandr/features/gamma.py
+++ b/winrandr/features/gamma.py
@@ -75,6 +75,25 @@ def _modify(ramp: c_uint16) -> None:
     return ok
 
 
+def set_night_mode(device_name: str, strength: float) -> bool:
+    """通过衰减蓝光设置夜间模式。
+
+    strength: 0.0-1.0，0 为无变化，1 为完全移除蓝光。
+    """
+    if not 0.0 <= strength <= 1.0:
+        logger.error("夜间模式强度必须在 0.0-1.0 之间: %g", strength)
+        return False
+
+    def _modify(ramp: c_uint16) -> None:
+        for i in range(512, 768):
+            ramp[i] = max(0, min(65535, int(ramp[i] * (1.0 - strength))))
+
+    ok = _apply_gamma(device_name, _modify)
+    if ok:
+        logger.debug("设置 %s 夜间模式强度为 %.2f", device_name, strength)
+    return ok
+
+
 def identify_display(device_name: str, duration: float = 2.0) -> bool:
     """通过闪烁屏幕帮助识别指定显示器（闪 3 次后恢复原状）。"""
     try: