diff --git a/track-uniapp/src/pages/scan/components/TreeCanvas.vue b/track-uniapp/src/pages/scan/components/TreeCanvas.vue
index 29118a6..47ad6a9 100644
--- a/track-uniapp/src/pages/scan/components/TreeCanvas.vue
+++ b/track-uniapp/src/pages/scan/components/TreeCanvas.vue
@@ -83,12 +83,22 @@ export default {
       const CARD_W = 160, CARD_H = 80, GAP_X = 24, GAP_Y = 24;
       const CENTER_X = 0;  // 中央主干 X
 
-      // 拍平 + 深拷贝
+      // 🔧 浅拷贝所有 task 对象，避免修改响应式原始数据导致无限渲染循环
       const flatMap = {};
       const allTasks = [];
-      const walk = (tasks) => { if (!tasks) return; tasks.forEach(t => { allTasks.push(t); flatMap[t.id] = t; walk(t.child_tasks); }); };
+      const walk = (tasks) => { if (!tasks) return; tasks.forEach(t => { const copy = { ...t }; allTasks.push(copy); flatMap[copy.id] = copy; walk(t.child_tasks); }); };
       walk(this.product.task_tree);
 
+      // 重建父子引用（child_tasks 指向副本）
+      allTasks.forEach(t => {
+        if (t.child_tasks && t.child_tasks.length) {
+          t.child_tasks = t.child_tasks.map(c => flatMap[c.id]).filter(Boolean);
+        }
+        if (t.parent_task_id) {
+          t.parent = flatMap[t.parent_task_id] || null;
+        }
+      });
+
       // 分支编号
       const branchLabelMap = {};
       const traverse = (tasks, prefix) => {
@@ -101,7 +111,9 @@ export default {
           else { si++; const n = prefix ? prefix + '.' + si : '' + si; branchLabelMap[t.id] = '分支 ' + n; traverse(t.child_tasks, n); }
         });
       };
-      this.product.task_tree.forEach(t => { branchLabelMap[t.id] = '主分支'; traverse(t.child_tasks, ''); });
+      // 遍历顶层时使用副本引用
+      const rootCopies = this.product.task_tree.map(t => flatMap[t.id]).filter(Boolean);
+      rootCopies.forEach(t => { branchLabelMap[t.id] = '主分支'; traverse(t.child_tasks, ''); });
 
       // 主管分类
       const mains = []; const subs = []; const subByParent = {};
@@ -117,25 +129,27 @@ export default {
       const nodes = [];
       const childSeen = new Set();
       mains.forEach((m, mi) => {
-        m.x = CENTER_X; m.y = mi * (CARD_H + GAP_Y) * 2;
-        m._isMain = true; m._blabel = '主分支';
-        nodes.push(m);
+        const node = { ...m, x: CENTER_X, y: mi * (CARD_H + GAP_Y) * 2, _isMain: true, _blabel: '主分支' };
+        nodes.push(node);
+        // 更新 flatMap 引用以便 lines/arrows 计算使用正确的坐标
+        flatMap[node.id] = node;
 
         const children = subByParent[m.id] || [];
         children.sort((a, b) => new Date(a.created_at) - new Date(b.created_at));
         children.forEach((c, ci) => {
           const isLeft = ci % 2 === 0;
           const dist = Math.floor(ci / 2) + 1;
-          c.y = m.y;
-          c.x = isLeft ? CENTER_X - dist * (CARD_W + GAP_X) : CENTER_X + dist * (CARD_W + GAP_X);
-          c._isMain = false; c._blabel = branchLabelMap[c.id] || '分支';
-          nodes.push(c);
+          const childNode = { ...c, y: node.y,
+            x: isLeft ? CENTER_X - dist * (CARD_W + GAP_X) : CENTER_X + dist * (CARD_W + GAP_X),
+            _isMain: false, _blabel: branchLabelMap[c.id] || '分支' };
+          nodes.push(childNode);
+          flatMap[childNode.id] = childNode;
           childSeen.add(c.id);
         });
       });
 
       // 遗留分支（父任务不在 mains 中的）
-      subs.forEach(s => { if (!childSeen.has(s.id)) { s.x = 200; s.y = nodes.length ? nodes[nodes.length - 1].y + CARD_H + GAP_Y : 0; s._isMain = false; s._blabel = '分支'; nodes.push(s); } });
+      subs.forEach(s => { if (!childSeen.has(s.id)) { const legacyNode = { ...s, x: 200, y: nodes.length ? nodes[nodes.length - 1].y + CARD_H + GAP_Y : 0, _isMain: false, _blabel: '分支' }; nodes.push(legacyNode); flatMap[legacyNode.id] = legacyNode; } });
 
       // 加上全局偏移
       const padding = 40;