diff --git a/backend/app/api/settings.py b/backend/app/api/settings.py
index a106025..8e062b8 100644
--- a/backend/app/api/settings.py
+++ b/backend/app/api/settings.py
@@ -781,6 +781,19 @@ def update_realtime_quotes(req: RealtimeQuotesPrefs, request: Request) -> dict:
     """
     from app.services import preferences
     qs = getattr(request.app.state, "quote_service", None)
+    depth_svc = getattr(request.app.state, "depth_service", None)
+
+    def _sync_depth_polling(realtime_on: bool) -> None:
+        """实时行情开关联动 depth 盘中轮询: 开→恢复(仍受监控开关/能力门控), 关→立即停。
+
+        实时行情关闭时 enriched 停留在上一交易日, depth 轮询只会反复拉陈旧名单。
+        """
+        if not depth_svc:
+            return
+        if realtime_on:
+            depth_svc.start_polling()
+        else:
+            depth_svc.stop_polling()
 
     allowed = qs.is_realtime_allowed() if qs else True
     if req.realtime_quotes_enabled and not allowed:
@@ -788,12 +801,14 @@ def update_realtime_quotes(req: RealtimeQuotesPrefs, request: Request) -> dict:
         preferences.save({"realtime_quotes_enabled": False})
         if qs:
             qs.disable()
+        _sync_depth_polling(False)
         return {"realtime_quotes_enabled": False, "realtime_allowed": False}
     if req.realtime_quotes_enabled and qs and qs.is_paused():
         # 管道/数据修正运行期间禁止开启实时行情 — 防止写盘竞态
         raise HTTPException(status_code=409, detail="数据同步运行中，实时行情已临时暂停，请稍后再开启")
     if req.realtime_quotes_enabled and qs and qs.realtime_mode() == "watchlist" and not preferences.get_realtime_watchlist_symbols():
         preferences.save({"realtime_quotes_enabled": False})
+        _sync_depth_polling(False)
         return {"realtime_quotes_enabled": False, "realtime_allowed": True, "mode": "watchlist", "error": "watchlist_empty"}
 
     preferences.save({"realtime_quotes_enabled": req.realtime_quotes_enabled})
@@ -802,6 +817,7 @@ def update_realtime_quotes(req: RealtimeQuotesPrefs, request: Request) -> dict:
             qs.enable()
         else:
             qs.disable()
+    _sync_depth_polling(req.realtime_quotes_enabled)
 
     return {"realtime_quotes_enabled": req.realtime_quotes_enabled, "realtime_allowed": allowed}
 
diff --git a/backend/app/services/depth_service.py b/backend/app/services/depth_service.py
index c239530..9e7abcf 100644
--- a/backend/app/services/depth_service.py
+++ b/backend/app/services/depth_service.py
@@ -146,12 +146,19 @@ class DepthService:
             logger.warning("depth sealed 从 parquet 恢复失败: %s", e)
 
     def start_polling(self) -> None:
-        """启动盘中轮询线程(连板梯队监控开启 + 有能力 + 交易时段)。"""
+        """启动盘中轮询线程(连板梯队监控开启 + 实时行情开启 + 有能力)。
+
+        依赖实时行情开关: 实时行情关闭时 enriched 内存缓存停留在上一交易日,
+        轮询会反复拉取陈旧的涨跌停名单(浪费 API 额度且数据无意义)。
+        实时行情开关切换时由 settings API 调 stop_polling/start_polling 同步启停。
+        """
         if not self._has_capability():
             return
         from app.services import preferences
         if not preferences.get_limit_ladder_monitor_enabled():
             return
+        if not preferences.get_realtime_quotes_enabled():
+            return
         # check-then-act 加锁: 两个线程同时 start_polling 不会各起一个轮询线程
         with self._lock:
             if self._running: