diff --git a/inventory-web/src/api/inbound/buy.ts b/inventory-web/src/api/inbound/buy.ts
index e0108b4..9b0706a 100644
--- a/inventory-web/src/api/inbound/buy.ts
+++ b/inventory-web/src/api/inbound/buy.ts
@@ -54,6 +54,15 @@ export function searchMaterialBase(keyword: string, page: number = 1, company?:
     })
 }
 
+// 6.1 按物料精准取“最近一次采购入库记录”（批号自增用；不再全局拉前 N 条再前端过滤）
+export function getBuyLatestRecord(baseId: number) {
+    return request({
+        url: '/inbound/buy/latest-record',
+        method: 'get',
+        params: { base_id: baseId }
+    })
+}
+
 // 7. 文件上传
 export function uploadFile(data: FormData) {
     return request({
diff --git a/inventory-web/src/views/stock/inbound/buy.vue b/inventory-web/src/views/stock/inbound/buy.vue
index 4fb0b34..a5be10a 100644
--- a/inventory-web/src/views/stock/inbound/buy.vue
+++ b/inventory-web/src/views/stock/inbound/buy.vue
@@ -799,7 +799,8 @@ import {
   getSupplierSuggestions,
   getUserSuggestions,
   getLocationSuggestions,
-  getFilterOptions
+  getFilterOptions,
+  getBuyLatestRecord
 } from '@/api/inbound/buy'
 import { getApprovedUnstockedRequests } from '@/api/purchase'
 import {getLabelPreview, executePrint} from '@/api/common/print'
@@ -1352,24 +1353,25 @@ const rules = computed(() => {
 
 const checkHistoryAndSetMode = async (baseId: number) => {
   try {
-    const res: any = await getBuyList({page: 1, pageSize: 1000})
-    const historyItems = (res.data.items || []).filter((item: any) => item.base_id === baseId)
+    // ★ 改用后端“按物料精准取最近一条”接口（O(1)、不分页、不受历史行数/前1000条截断影响）
+    const res: any = await getBuyLatestRecord(baseId)
+    const rec = res?.data || {}
 
-    if (historyItems.length > 0) {
+    if (rec.has_history) {
       modeLocked.value = true
-      const latest = historyItems.sort((a: any, b: any) => b.id - a.id)[0]
-      if (latest.serial_number) {
+      if (rec.mode === 'serial') {
         entryMode.value = 'serial'
         form.serial_number = ''
         form.batch_number = ''
       } else {
         entryMode.value = 'batch'
         form.serial_number = ''
-        form.batch_number = incrementBatchNumber(latest.batch_number || '000000')
+        form.batch_number = incrementBatchNumber(rec.latest_batch || '000000')
       }
     } else {
       modeLocked.value = false
       entryMode.value = 'batch'
+      form.serial_number = ''
       form.batch_number = '000001'
     }
     if (formRef.value) {
@@ -1379,6 +1381,7 @@ const checkHistoryAndSetMode = async (baseId: number) => {
   } catch (e) {
     modeLocked.value = false
     entryMode.value = 'batch'
+    form.serial_number = ''
     form.batch_number = '000001'
   }
 }
@@ -1916,10 +1919,11 @@ const confirmPurchaseImport = () => {
       isInspectionRequired: mat.is_inspection_required
     }]
   } else if (po.base_id) {
-    // 如果 material 为空但 base_id 有值，尝试通过 base_id 查询
-    // 这里简单处理：直接设置 base_id 让用户手动搜索
+    // 如果 material 为空但 base_id 有值：仍按 base_id 续批号/带历史库位，物料详情让用户手动搜索确认
     form.base_id = po.base_id
-    ElMessage.info('该采购单未附带物料详情，已填充 base_id，请手动搜索物料确认')
+    checkHistoryAndSetMode(po.base_id)
+    fetchLastLocation(po.base_id)
+    ElMessage.info('该采购单未附带物料详情，已按物料填充批号/库位，请手动搜索确认物料信息')
   } else {
     ElMessage.warning('该采购单未关联基础物料，无法自动填充物料信息')
     return