diff --git a/app/services/notify_dispatch.py b/app/services/notify_dispatch.py
index c06b204..0c3c32c 100644
--- a/app/services/notify_dispatch.py
+++ b/app/services/notify_dispatch.py
@@ -292,17 +292,20 @@ def _get_notify_persons(camera_id: str, alarm_level: int) -> tuple:
         db.close()
 
 
-# 区域名称缓存（area_id → area_name），避免重复查询
-_area_name_cache: Dict[int, str] = {}
+# 区域名称缓存（area_id → (area_name, expire_time)），5 分钟 TTL
+_area_name_cache: Dict[int, tuple] = {}
 _iot_token_cache: Dict[str, str] = {"token": "", "expire": 0}
 
+_AREA_CACHE_TTL = 300  # 5 分钟
+
 
 async def _get_area_name_from_iot(area_id: int) -> str:
-    """从 IoT 平台查询区域名称（带缓存）"""
+    """从 IoT 平台查询区域名称（带 TTL 缓存）"""
     if not area_id:
         return ""
-    if area_id in _area_name_cache:
-        return _area_name_cache[area_id]
+    cached = _area_name_cache.get(area_id)
+    if cached and cached[1] > __import__('time').time():
+        return cached[0]
     try:
         import httpx
         import time
@@ -338,7 +341,7 @@ async def _get_area_name_from_iot(area_id: int) -> str:
             if data.get("code") == 0 and data.get("data"):
                 name = data["data"].get("areaName", "")
                 if name:
-                    _area_name_cache[area_id] = name
+                    _area_name_cache[area_id] = (name, __import__('time').time() + _AREA_CACHE_TTL)
                     return name
     except Exception as e:
         logger.warning(f"查询IoT平台区域名失败: area_id={area_id}, error={e}")