diff --git a/src/web/task_manager.py b/src/web/task_manager.py
index b9e31b9..31c620b 100644
--- a/src/web/task_manager.py
+++ b/src/web/task_manager.py
@@ -16,9 +16,12 @@ logger = logging.getLogger(__name__)
 # 全局线程池（支持最多 50 个并发注册任务）
 _executor = ThreadPoolExecutor(max_workers=50, thread_name_prefix="reg_worker")
 
+# 全局元锁：保护所有 defaultdict 的首次 key 创建（避免多线程竞态）
+_meta_lock = threading.Lock()
+
 # 任务日志队列 (task_uuid -> list of logs)
 _log_queues: Dict[str, List[str]] = defaultdict(list)
-_log_locks: Dict[str, threading.Lock] = defaultdict(threading.Lock)
+_log_locks: Dict[str, threading.Lock] = {}
 
 # WebSocket 连接管理 (task_uuid -> list of websockets)
 _ws_connections: Dict[str, List] = defaultdict(list)
@@ -36,7 +39,25 @@ _task_cancelled: Dict[str, bool] = {}
 # 批量任务状态 (batch_id -> dict)
 _batch_status: Dict[str, dict] = {}
 _batch_logs: Dict[str, List[str]] = defaultdict(list)
-_batch_locks: Dict[str, threading.Lock] = defaultdict(threading.Lock)
+_batch_locks: Dict[str, threading.Lock] = {}
+
+
+def _get_log_lock(task_uuid: str) -> threading.Lock:
+    """线程安全地获取或创建任务日志锁"""
+    if task_uuid not in _log_locks:
+        with _meta_lock:
+            if task_uuid not in _log_locks:
+                _log_locks[task_uuid] = threading.Lock()
+    return _log_locks[task_uuid]
+
+
+def _get_batch_lock(batch_id: str) -> threading.Lock:
+    """线程安全地获取或创建批量任务日志锁"""
+    if batch_id not in _batch_locks:
+        with _meta_lock:
+            if batch_id not in _batch_locks:
+                _batch_locks[batch_id] = threading.Lock()
+    return _batch_locks[batch_id]
 
 
 class TaskManager:
@@ -77,7 +98,7 @@ class TaskManager:
                 logger.warning(f"推送日志到 WebSocket 失败: {e}")
 
         # 广播后再添加到队列
-        with _log_locks[task_uuid]:
+        with _get_log_lock(task_uuid):
             _log_queues[task_uuid].append(log_message)
 
     async def _broadcast_log(self, task_uuid: str, log_message: str):
@@ -132,7 +153,7 @@ class TaskManager:
             if websocket not in _ws_connections[task_uuid]:
                 _ws_connections[task_uuid].append(websocket)
                 # 记录已发送的日志数量，用于发送历史日志时避免重复
-                with _log_locks[task_uuid]:
+                with _get_log_lock(task_uuid):
                     _ws_sent_index[task_uuid][id(websocket)] = len(_log_queues.get(task_uuid, []))
                 logger.info(f"WebSocket 连接已注册: {task_uuid}")
             else:
@@ -144,7 +165,7 @@ class TaskManager:
             ws_id = id(websocket)
             sent_count = _ws_sent_index.get(task_uuid, {}).get(ws_id, 0)
 
-        with _log_locks[task_uuid]:
+        with _get_log_lock(task_uuid):
             all_logs = _log_queues.get(task_uuid, [])
             unsent_logs = all_logs[sent_count:]
             # 更新已发送索引
@@ -166,7 +187,7 @@ class TaskManager:
 
     def get_logs(self, task_uuid: str) -> List[str]:
         """获取任务的所有日志"""
-        with _log_locks[task_uuid]:
+        with _get_log_lock(task_uuid):
             return _log_queues.get(task_uuid, []).copy()
 
     def update_status(self, task_uuid: str, status: str, **kwargs):
@@ -217,7 +238,7 @@ class TaskManager:
                 logger.warning(f"推送批量日志到 WebSocket 失败: {e}")
 
         # 广播后再添加到队列
-        with _batch_locks[batch_id]:
+        with _get_batch_lock(batch_id):
             _batch_logs[batch_id].append(log_message)
 
     async def _broadcast_batch_log(self, batch_id: str, log_message: str):
@@ -285,7 +306,7 @@ class TaskManager:
 
     def get_batch_logs(self, batch_id: str) -> List[str]:
         """获取批量任务日志"""
-        with _batch_locks[batch_id]:
+        with _get_batch_lock(batch_id):
             return _batch_logs.get(batch_id, []).copy()
 
     def is_batch_cancelled(self, batch_id: str) -> bool:
@@ -310,7 +331,7 @@ class TaskManager:
             if websocket not in _ws_connections[key]:
                 _ws_connections[key].append(websocket)
                 # 记录已发送的日志数量，用于发送历史日志时避免重复
-                with _batch_locks[batch_id]:
+                with _get_batch_lock(batch_id):
                     _ws_sent_index[key][id(websocket)] = len(_batch_logs.get(batch_id, []))
                 logger.info(f"批量任务 WebSocket 连接已注册: {batch_id}")
             else:
@@ -323,7 +344,7 @@ class TaskManager:
             ws_id = id(websocket)
             sent_count = _ws_sent_index.get(key, {}).get(ws_id, 0)
 
-        with _batch_locks[batch_id]:
+        with _get_batch_lock(batch_id):
             all_logs = _batch_logs.get(batch_id, [])
             unsent_logs = all_logs[sent_count:]
             # 更新已发送索引