diff --git a/services/cache.py b/services/cache.py
index 73d63f7..89dc7ae 100644
--- a/services/cache.py
+++ b/services/cache.py
@@ -292,6 +292,14 @@ class MaterialCache:
             for file_info in cache_files:
                 if total_size <= target_size:
                     break
+                # 从文件名提取 cache_key，检查是否有锁（说明正在被使用）
+                filename = os.path.basename(file_info['path'])
+                cache_key = os.path.splitext(filename)[0]
+                lock_path = self._get_lock_path(cache_key)
+                if os.path.exists(lock_path):
+                    # 该文件正在被其他任务使用，跳过删除
+                    logger.debug(f"Cache cleanup: skipping locked file {filename}")
+                    continue
                 try:
                     os.remove(file_info['path'])
                     total_size -= file_info['size']