diff --git a/backend/server.py b/backend/server.py
index ca23f28..8998d54 100644
--- a/backend/server.py
+++ b/backend/server.py
@@ -2804,6 +2804,7 @@ def handle_delete_task_process_node(data):
                                 for branch in branches_list:
                                     if branch.get('id') == branch_id:
                                         # 找到目标分支，删除指定的节点
+                                        target_branch_content = branch.get('branchContent')  # 保存branchContent用于匹配flow_branches
                                         nodes = branch.get('nodes', [])
                                         tasks = branch.get('tasks', [])
 
@@ -2815,14 +2816,47 @@ def handle_delete_task_process_node(data):
                                                 break
 
                                         if node_to_delete:
+                                            # 先获取 original_index（删除前获取，用于同步 flow_branches）
+                                            node_data = node_to_delete.get('data', {})
+                                            original_index = node_data.get('originalIndex')
+
+                                            # ========== 同步更新 flow_branches (在删除前执行) ==========
+                                            if original_index is not None:
+                                                flow_branches = existing_branches.get('flow_branches', [])
+                                                if isinstance(flow_branches, list):
+                                                    # 在 nodes 中查找并删除
+                                                    for flow_branch in flow_branches:
+                                                        flow_nodes = flow_branch.get('nodes', [])
+                                                        if isinstance(flow_nodes, list):
+                                                            for flow_node in flow_nodes:
+                                                                flow_node_data = flow_node.get('data', {})
+                                                                task_data = flow_node_data.get('task', {})
+                                                                if task_data.get('Id') == step_id:
+                                                                    task_process = task_data.get('TaskProcess', [])
+                                                                    if 0 <= original_index < len(task_process):
+                                                                        task_process.pop(original_index)
+                                                                        task_data['TaskProcess'] = task_process
+                                                                    break
+
+                                                    # 在 tasks 中查找并删除
+                                                    for flow_branch in flow_branches:
+                                                        flow_tasks = flow_branch.get('tasks', [])
+                                                        if isinstance(flow_tasks, list):
+                                                            for task_item in flow_tasks:
+                                                                if task_item.get('Id') == step_id:
+                                                                    task_process = task_item.get('TaskProcess', [])
+                                                                    if 0 <= original_index < len(task_process):
+                                                                        task_process.pop(original_index)
+                                                                        task_item['TaskProcess'] = task_process
+                                                                    break
+
+                                                    existing_branches['flow_branches'] = flow_branches
+                                            # ========== 同步更新 flow_branches 结束 ==========
+
                                             # 从 nodes 中删除
                                             nodes = [n for n in nodes if n.get('id') != node_id]
 
                                             # 从 tasks 中删除：使用 originalIndex 精确匹配
-                                            # nodes 包含 root 节点，所以 agent 节点的 originalIndex 对应 tasks 的索引
-                                            node_data = node_to_delete.get('data', {})
-                                            original_index = node_data.get('originalIndex')
-
                                             if original_index is not None and 0 <= original_index < len(tasks):
                                                 tasks.pop(original_index)
                                             else: