diff --git a/track-uniapp/src/pages/scan/components/TreeCanvas.vue b/track-uniapp/src/pages/scan/components/TreeCanvas.vue
index 222ccde..e83b9bd 100644
--- a/track-uniapp/src/pages/scan/components/TreeCanvas.vue
+++ b/track-uniapp/src/pages/scan/components/TreeCanvas.vue
@@ -66,8 +66,12 @@ export default {
       const layout = (tasks, parentRowIdx, parentX) => {
         if (!tasks || !tasks.length) return;
         tasks.forEach(t => {
-          // 判定：parent COMPLETED → 串行 Y+1；parent WIP/PENDING → 并行同Y偏右
-          const isSerial = !t.parent_task_id || (this.taskStatusMap[t.parent_task_id] === 'COMPLETED');
+          // 时间戳判定：子任务创建于父任务完成之后 → 串行(下一行)；否则 → 并行(同Y偏右)
+          const parentNode = this.taskDataMap[t.parent_task_id];
+          const isSerial = !t.parent_task_id || (
+            parentNode && parentNode.completed_at &&
+            new Date(t.created_at) > new Date(parentNode.completed_at)
+          );
           const rowIdx = isSerial ? (parentRowIdx >= 0 ? parentRowIdx + 1 : rows.length) : parentRowIdx;
           while (rows.length <= rowIdx) rows.push({ y: 0, tasks: [] });
 
@@ -100,9 +104,9 @@ export default {
 
       return nodes;
     },
-    taskStatusMap() {
+    taskDataMap() {
       const map = {};
-      const walk = (tasks) => { if (!tasks) return; tasks.forEach(t => { map[t.id] = t.status; walk(t.child_tasks); }); };
+      const walk = (tasks) => { if (!tasks) return; tasks.forEach(t => { map[t.id] = t; walk(t.child_tasks); }); };
       if (this.product) walk(this.product.task_tree);
       return map;
     },