diff --git a/backend/src/main/java/com/designhub/service/TaskItemService.java b/backend/src/main/java/com/designhub/service/TaskItemService.java
index ed51e54..4053857 100644
--- a/backend/src/main/java/com/designhub/service/TaskItemService.java
+++ b/backend/src/main/java/com/designhub/service/TaskItemService.java
@@ -18,8 +18,10 @@ import org.springframework.transaction.annotation.Transactional;
 
 import java.time.LocalDateTime;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 /**
  * 任务子项服务类（流水线任务）
@@ -507,7 +509,7 @@ public class TaskItemService {
 
                     // 发送通知给接单部门负责人
                     // 从子任务的任务类型配置中获取allowed_dept_ids
-                    Set<Long> notifiedLeaderIds = new java.util.HashSet<>();
+                    Set<Long> notifiedLeaderIds = new HashSet<>();
                     for (TaskItem nextItem : nextGroupItems) {
                         Long targetDeptId = getTargetDeptIdFromTaskType(nextItem.getTaskTypeId());
                         if (targetDeptId != null) {