diff --git a/backend/alembic/versions/a7b8c9d0e1f2_add_task_type.py b/backend/alembic/versions/a7b8c9d0e1f2_add_task_type.py
new file mode 100644
index 0000000..d1fd82b
--- /dev/null
+++ b/backend/alembic/versions/a7b8c9d0e1f2_add_task_type.py
@@ -0,0 +1,24 @@
+"""add_task_type
+
+Revision ID: a7b8c9d0e1f2
+Revises: f6a7b8c9d0e1
+Create Date: 2026-08-06
+"""
+from typing import Sequence, Union
+from alembic import op
+import sqlalchemy as sa
+
+revision: str = "a7b8c9d0e1f2"
+down_revision: Union[str, None] = "f6a7b8c9d0e1"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.add_column("tasks", sa.Column("task_type", sa.String(20), nullable=True, comment="派生类型: TRANSFER/SPAWN/RECOVERY"))
+    # 刷老数据：parent_task_id 非空的默认为 TRANSFER
+    op.execute("UPDATE tasks SET task_type = 'TRANSFER' WHERE parent_task_id IS NOT NULL AND task_type IS NULL")
+
+
+def downgrade() -> None:
+    op.drop_column("tasks", "task_type")
diff --git a/backend/app/models/task.py b/backend/app/models/task.py
index 50543dc..486a734 100644
--- a/backend/app/models/task.py
+++ b/backend/app/models/task.py
@@ -70,6 +70,9 @@ class Task(Base):
     is_rework: Mapped[bool] = mapped_column(
         Boolean, default=False, comment="是否为返工任务",
     )
+    task_type: Mapped[str | None] = mapped_column(
+        String(20), nullable=True, comment="任务派生类型: TRANSFER/SPAWN/RECOVERY/null=历史数据",
+    )
     remark: Mapped[str | None] = mapped_column(
         String(2000), nullable=True, comment="任务初始描述/交接备注",
     )
diff --git a/backend/app/schemas/task.py b/backend/app/schemas/task.py
index 3ea2bf8..246d85c 100644
--- a/backend/app/schemas/task.py
+++ b/backend/app/schemas/task.py
@@ -131,6 +131,7 @@ class TaskResponse(BaseModel):
     status: str
     notify_parent_on_complete: bool
     is_rework: bool = False
+    task_type: str | None = None
     remark: str | None = None
     reject_reason: str | None = None
     received_at: datetime | None = None
diff --git a/backend/app/services/task_service.py b/backend/app/services/task_service.py
index 94f73b9..c7245f2 100644
--- a/backend/app/services/task_service.py
+++ b/backend/app/services/task_service.py
@@ -112,6 +112,7 @@ def _to_flat_response(task: Task) -> TaskResponse:
         status=task.status,
         notify_parent_on_complete=task.notify_parent_on_complete,
         is_rework=task.is_rework,
+        task_type=task.task_type,
         remark=task.remark,
         reject_reason=task.reject_reason,
         received_at=task.received_at,
@@ -143,6 +144,7 @@ def _to_response(task: Task) -> TaskResponse:
         status=task.status,
         notify_parent_on_complete=task.notify_parent_on_complete,
         is_rework=task.is_rework,
+        task_type=task.task_type,
         remark=task.remark,
         reject_reason=task.reject_reason,
         received_at=task.received_at,
@@ -335,6 +337,7 @@ async def recall_task(
         task_name=task.task_name,
         assignee_id=operator_id,
         status=TASK_STATUS_WIP,
+        task_type="RECOVERY",
         notify_parent_on_complete=False,
         is_rework=False,
         remark=f"撤回「{task.task_name}」后重新接手",
@@ -377,6 +380,7 @@ async def spawn_subtask(
         task_name=data.task_name,
         assignee_id=data.assignee_id,
         status=TASK_STATUS_PENDING,
+        task_type="SPAWN",
         notify_parent_on_complete=False,
         is_rework=False,
         remark=data.remark or None,
@@ -671,6 +675,7 @@ async def transfer_task(
             task_name=task_name,
             assignee_id=assignee_id,
             status=TASK_STATUS_PENDING,
+            task_type="TRANSFER",
             notify_parent_on_complete=False,
             is_rework=False,
             remark=request.note or None,
diff --git a/track-uniapp/src/pages/scan/components/TreeCanvas.vue b/track-uniapp/src/pages/scan/components/TreeCanvas.vue
index b9f0c18..aac2713 100644
--- a/track-uniapp/src/pages/scan/components/TreeCanvas.vue
+++ b/track-uniapp/src/pages/scan/components/TreeCanvas.vue
@@ -59,55 +59,60 @@ export default {
 
       const CARD_W = 320, CARD_H = 460, GAP_X = 80, GAP_Y = 120;
       const nodes = [];
+      const rowMaxX = {};
+      let currentMaxYIdx = -1;
 
-      // 按行组织：每行是一个 { y, tasks: [...] }
-      const rows = [];
+      const flatMap = {};
+      const flatten = (tasks) => {
+        if (!tasks) return;
+        tasks.forEach(t => { flatMap[t.id] = t; flatten(t.child_tasks); });
+      };
+      flatten(this.product.task_tree);
 
-      const layout = (tasks, parentRowIdx, parentX) => {
-        if (!tasks || !tasks.length) return;
-        tasks.forEach(t => {
-          // 工业拓扑：父WIP→并行(同Y)；父COMPLETED→串行(换行)
-          // 后端保证 COMPLETED 后不可 spawn，故 COMPLETED 的子任务必为转交产物
-          const parent = this.taskDataMap[t.parent_task_id];
-          const isSerial = !t.parent_task_id || (parent && (parent.status === 'COMPLETED' || parent.status === 'CANCELED'));
-          const rowIdx = isSerial ? (parentRowIdx >= 0 ? parentRowIdx + 1 : rows.length) : parentRowIdx;
-          while (rows.length <= rowIdx) rows.push({ y: 0, tasks: [] });
+      const layoutNode = (t) => {
+        if (t._visited) return;
+        t._visited = true;
 
-          const row = rows[rowIdx];
-          const x = row.tasks.length === 0 ? 40 : row.tasks[row.tasks.length - 1]._xEnd + GAP_X;
-          const node = { ...t, x, y: 0, _rowIdx: rowIdx, _xEnd: x + CARD_W };
-          row.tasks.push(node);
-          nodes.push(node);
-        });
+        if (!t.parent_task_id) {
+          // 规则A：根节点 → 新行 X=0
+          currentMaxYIdx++;
+          t._yIdx = currentMaxYIdx;
+          t._xIdx = 0;
+        } else {
+          const parent = flatMap[t.parent_task_id];
+          if (parent && !parent._visited) layoutNode(parent);
 
-        // 递归子任务
-        tasks.forEach(t => {
-          if (t.child_tasks && t.child_tasks.length) {
-            const parentNode = nodes.find(n => n.id === t.id);
-            const parentRow = parentNode ? parentNode._rowIdx : rows.length - 1;
-            layout(t.child_tasks, parentRow, parentNode ? parentNode.x : 40);
+          const type = t.task_type || (parent && parent.status === 'CANCELED' ? 'RECOVERY' : 'SPAWN');
+
+          if (type === 'SPAWN') {
+            t._yIdx = parent._yIdx;
+            t._xIdx = (rowMaxX[t._yIdx] !== undefined ? rowMaxX[t._yIdx] : 0) + 1;
+          } else if (type === 'TRANSFER' || type === 'MAIN') {
+            currentMaxYIdx++;
+            t._yIdx = currentMaxYIdx;
+            t._xIdx = 0;
+          } else if (type === 'RECOVERY') {
+            currentMaxYIdx++;
+            t._yIdx = currentMaxYIdx;
+            t._xIdx = parent._xIdx;
           }
-        });
+        }
+
+        rowMaxX[t._yIdx] = Math.max(rowMaxX[t._yIdx] || 0, t._xIdx);
+        t.x = 40 + t._xIdx * (CARD_W + GAP_X);
+        t.y = 20 + t._yIdx * (CARD_H + GAP_Y);
+        nodes.push(t);
+
+        if (t.child_tasks && t.child_tasks.length) {
+          t.child_tasks
+            .sort((a, b) => (a.task_type === 'TRANSFER' ? -1 : 1))
+            .forEach(child => layoutNode(child));
+        }
       };
 
-      layout(this.product.task_tree, -1, 40);
-
-      // 计算 Y 坐标
-      let curY = 20;
-      rows.forEach(row => {
-        row.y = curY;
-        row.tasks.forEach(n => { n.y = curY; });
-        curY += CARD_H + GAP_Y;
-      });
-
+      this.product.task_tree.forEach(root => layoutNode(root));
       return nodes;
     },
-    taskDataMap() {
-      const map = {};
-      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;
-    },
     branchLabelMap() {
       const map = {};
       if (!this.product || !this.product.task_tree) return map;