diff --git a/backend/src/main/java/com/designhub/service/TaskService.java b/backend/src/main/java/com/designhub/service/TaskService.java
index 545681a..ad726d8 100644
--- a/backend/src/main/java/com/designhub/service/TaskService.java
+++ b/backend/src/main/java/com/designhub/service/TaskService.java
@@ -2952,13 +2952,14 @@ public class TaskService {
             for (TaskItem item : taskItems) {
                 item.setStatus("in_progress");
                 item.setIsLocked(0);
-                // 如果子任务还没有接收人，设置为主任务的接收人
-                if (item.getReceiverId() == null && receiverId != null) {
+                // 指派模式下：强制更新所有子任务的接收人为主任务的接收人
+                if (receiverId != null) {
                     item.setReceiverId(receiverId);
                     if (receiverDeptId != null) {
                         item.setReceiverDeptId(receiverDeptId);
                     }
-                    log.info("子任务 {} 已设置接收人: {}", item.getId(), receiverId);
+                    log.info("并行流水线子任务 {} 已设置/更新接收人: receiverId={}, deptId={}", 
+                            item.getId(), receiverId, receiverDeptId);
                 }
                 taskItemMapper.updateById(item);
             }
@@ -2970,13 +2971,14 @@ public class TaskService {
                 if (item.getGroupNo().equals(firstGroupNo)) {
                     item.setStatus("in_progress");
                     item.setIsLocked(0);
-                    // 如果子任务还没有接收人，设置为主任务的接收人
-                    if (item.getReceiverId() == null && receiverId != null) {
+                    // 指派模式下：强制更新第一组子任务的接收人为主任务的接收人
+                    if (receiverId != null) {
                         item.setReceiverId(receiverId);
                         if (receiverDeptId != null) {
                             item.setReceiverDeptId(receiverDeptId);
                         }
-                        log.info("子任务 {} 已设置接收人: {}", item.getId(), receiverId);
+                        log.info("顺序流水线第一组子任务 {} 已设置/更新接收人: receiverId={}, deptId={}", 
+                                item.getId(), receiverId, receiverDeptId);
                     }
                     taskItemMapper.updateById(item);
                     log.info("顺序流水线任务第一组子任务已更新为in_progress：itemId={}", item.getId());