diff --git a/apps/backend/src/services/worker-platform/admin-mock-work-order-service.ts b/apps/backend/src/services/worker-platform/admin-mock-work-order-service.ts
index 56054ce0..0398d772 100644
--- a/apps/backend/src/services/worker-platform/admin-mock-work-order-service.ts
+++ b/apps/backend/src/services/worker-platform/admin-mock-work-order-service.ts
@@ -3,7 +3,11 @@ import {
   normalizeWorkOrderAcceptanceMode,
   normalizeWorkOrderGiftCooldownHours,
 } from '../../domain/work-order-acceptance-mode.js'
-import { createWorkOrder, createWorkOrderEvent } from '../../repositories/worker-platform/index.js'
+import {
+  createWorkOrder,
+  createWorkOrderEvent,
+  listWorkOrdersByPlatformOrderId,
+} from '../../repositories/worker-platform/index.js'
 import type { JsonObject } from '../../types/json.js'
 import { createHttpError } from '../../utils/http.js'
 import { randomId } from '../../utils/random.js'
@@ -46,6 +50,18 @@ export async function createAdminMockWorkOrder(payload: JsonObject = {}) {
   const materialComplete = payload.materialComplete === true || payload.materialComplete === 'true'
   const fields = normalizeRequirementFields(payload.fields)
   const { platformOrderId, productName, shop } = input
+  // 订单号全局唯一：与自动同步的真实工单也不能撞号，否则打手按单号回填资料会命中多条。
+  const existingOrders = await listWorkOrdersByPlatformOrderId(platformOrderId)
+  if (existingOrders.length > 0) {
+    const existingNo = String(existingOrders[0]?.work_order_no || '').trim()
+    throw createHttpError(
+      `该订单号已存在工单${existingNo ? `（${existingNo}）` : ''}，请更换订单号`,
+      {
+        statusCode: 409,
+        errorCode: 'mock_work_order_platform_order_exists',
+      },
+    )
+  }
   const material = {
     ...(materialComplete
       ? {
diff --git a/apps/backend/src/services/worker-platform/sync-worker-orders-service.ts b/apps/backend/src/services/worker-platform/sync-worker-orders-service.ts
index e0f26980..5799acd7 100644
--- a/apps/backend/src/services/worker-platform/sync-worker-orders-service.ts
+++ b/apps/backend/src/services/worker-platform/sync-worker-orders-service.ts
@@ -9,6 +9,7 @@ import {
   createWorkOrder,
   createWorkOrderEvent,
   getWorkOrderByOrderItemId,
+  listWorkOrdersByPlatformOrderId,
   listWorkProductRuleMappings,
   listWorkProductRules,
   type WorkOrderRow,
@@ -88,6 +89,18 @@ export async function syncWorkerOrdersForSourceOrder(
       skipped.push({ orderItemId: Number(item.id), reason: 'already_exists' })
       continue
     }
+    // 订单号跨订单唯一：同一订单的多个 SKU 件允许共享订单号（按件建单是既有设计），
+    // 但订单号已挂在其他订单下时跳过，避免自动同步产生撞号工单。
+    const samePlatformOrders = await listWorkOrdersByPlatformOrderId(order.platform_order_id)
+    if (
+      samePlatformOrders.some((existing) => {
+        const existingOrderId = Number(existing.order_id || 0)
+        return existingOrderId > 0 && existingOrderId !== Number(order.id)
+      })
+    ) {
+      skipped.push({ orderItemId: Number(item.id), reason: 'platform_order_exists' })
+      continue
+    }
 
     const fields = normalizeRequirementFields(safeParseJson(rule.requirement_json).fields)
     const skuQuantity = resolveSkuNameQuantity(item.sku_name)
diff --git a/apps/frontend/src/pages/admin/panels/WorkOrderPanelParts.tsx b/apps/frontend/src/pages/admin/panels/WorkOrderPanelParts.tsx
index 598b83af..609ac2d2 100644
--- a/apps/frontend/src/pages/admin/panels/WorkOrderPanelParts.tsx
+++ b/apps/frontend/src/pages/admin/panels/WorkOrderPanelParts.tsx
@@ -111,6 +111,7 @@ export function MockWorkOrderForm({ onCreated }: { onCreated: () => Promise<void
         label="订单号"
         name="platformOrderId"
         rules={[{ required: true, whitespace: true, message: '请填写订单号' }]}
+        extra="订单号全局唯一，与已有工单重复将无法创建"
       >
         <Input placeholder="请输入订单号" />
       </Form.Item>