diff --git a/backend/src/main/java/com/designhub/service/TaskItemService.java b/backend/src/main/java/com/designhub/service/TaskItemService.java
index b544f21..9e67b87 100644
--- a/backend/src/main/java/com/designhub/service/TaskItemService.java
+++ b/backend/src/main/java/com/designhub/service/TaskItemService.java
@@ -701,7 +701,7 @@ public class TaskItemService {
             java.util.Set<String> receiverNames = new java.util.HashSet<>();
             for (TaskItem item : groupItems) {
                 if (item.getReceiverId() != null) {
-                    com.designhub.entity.User receiver = userMapper.selectById(item.getReceiverId());
+                    com.designhub.entity.User receiver = userService.getUserById(item.getReceiverId());
                     if (receiver != null) {
                         if (receiver.getPhone() != null) {
                             atMobiles.add(receiver.getPhone());