diff --git a/inventory-backend/app/services/inbound/buy_service.py b/inventory-backend/app/services/inbound/buy_service.py
index b2f14ef..8035957 100644
--- a/inventory-backend/app/services/inbound/buy_service.py
+++ b/inventory-backend/app/services/inbound/buy_service.py
@@ -4,6 +4,7 @@ from app.extensions import db
 from app.models.inbound.buy import StockBuy
 from app.models.inbound.product import StockProduct
 from app.models.base import MaterialBase
+from app.models.purchase import PurchaseRequest
 from datetime import datetime, timedelta, timezone
 from sqlalchemy import or_, func, text, and_
 from sqlalchemy.exc import IntegrityError
@@ -153,9 +154,27 @@ class BuyInboundService:
             in_qty = float(data.get('in_quantity') or 0)
             u_price = float(data.get('unit_price') or 0)
             tax_rate = float(data.get('tax_rate') or 0)
-            
-            # 计算税后单价
             post_tax_price = float(data.get('post_tax_unit_price') or 0)
+
+            # [新增] 按单入库：关联采购申请单
+            request_id = data.get('request_id')
+
+            # ★ 补价：库管角色没有 inbound_purchase:unit_price / total_price 权限，
+            #   采购单接口（api/v1/purchase.py）会把价格字段整个 pop 掉，前端导入时
+            #   因此带不出价（buy.vue 的 hasUnitPrice/hasTotalPrice 双双落空，
+            #   两个分支都不进）→ 入库成本被记成 0。
+            #   这里在落库前从采购申请单补回：价格**不经过前端**，库管依旧看不到
+            #   采购价，权限边界不变，但成本可追溯。
+            #   注：采购申请单的 unit_price 存的是**含税**单价（见 purchase/index.vue
+            #   的列名"含税单价"），需要反算不含税单价。
+            if request_id and u_price <= 0 and post_tax_price <= 0:
+                _req = PurchaseRequest.query.get(request_id)
+                if _req and float(_req.unit_price or 0) > 0:
+                    tax_rate = float(_req.tax_rate or 0)
+                    post_tax_price = float(_req.unit_price)
+                    u_price = post_tax_price / (1 + tax_rate / 100)
+            
+            # 计算税后单价（保底：只给了不含税价时反推）
             if post_tax_price == 0 and u_price > 0:
                 tax_multiplier = 1 + (tax_rate / 100)
                 post_tax_price = u_price * tax_multiplier
@@ -170,9 +189,6 @@ class BuyInboundService:
             generated_sku = str(next_global_id).zfill(10) if next_global_id else datetime.now().strftime('%Y%m%d%H%M%S')
             final_barcode = data.get('barcode') or generated_sku
 
-            # [新增] 按单入库：关联采购申请单
-            request_id = data.get('request_id')
-
             new_stock = StockBuy(
                 base_id=material.id, global_print_id=next_global_id, sku=generated_sku, barcode=final_barcode,
                 in_date=in_date_val, serial_number=data.get('serial_number'), batch_number=data.get('batch_number'),
@@ -201,8 +217,10 @@ class BuyInboundService:
             db.session.flush()  # 获取 new_stock.id
 
             # [新增] 按单入库：反写采购申请单状态为"已完成"
+            # 注：原先此处有一句局部 `from app.models.purchase import PurchaseRequest`，
+            #     它会让 Python 把 PurchaseRequest 视为本函数的局部变量，导致上方补价
+            #     逻辑（在 import 之前使用）抛 UnboundLocalError。已改用文件顶部的全局导入。
             if request_id:
-                from app.models.purchase import PurchaseRequest
                 purchase_req = db.session.get(PurchaseRequest, request_id)
                 if purchase_req:
                     if purchase_req.status != 1: