diff --git a/internal/handler/admin_master.go b/internal/handler/admin_master.go
index 9c2b6ee2..dcc4ca8d 100644
--- a/internal/handler/admin_master.go
+++ b/internal/handler/admin_master.go
@@ -349,7 +349,7 @@ func (h *Handler) CreateWarehouse(c *gin.Context) {
 		return
 	}
 	item.OrganizationID = orgID
-	if err := h.warehouseSvc.Save(&item); err != nil {
+	if err := h.warehouseSvc.Create(&item); err != nil {
 		response.BadRequest(c, err.Error())
 		return
 	}
@@ -369,7 +369,7 @@ func (h *Handler) UpdateWarehouse(c *gin.Context) {
 		return
 	}
 	item.ID, item.OrganizationID = id, orgID
-	if err := h.warehouseSvc.Save(&item); err != nil {
+	if err := h.warehouseSvc.Update(&item); err != nil {
 		response.BadRequest(c, err.Error())
 		return
 	}
@@ -389,7 +389,7 @@ func (h *Handler) CreateWarehouseLocation(c *gin.Context) {
 		return
 	}
 	item.WarehouseID = warehouseID
-	if err := h.warehouseSvc.SaveLocation(&item, orgID); err != nil {
+	if err := h.warehouseSvc.CreateLocation(&item, orgID); err != nil {
 		response.BadRequest(c, err.Error())
 		return
 	}
@@ -414,7 +414,7 @@ func (h *Handler) UpdateWarehouseLocation(c *gin.Context) {
 		return
 	}
 	item.ID, item.WarehouseID = locationID, warehouseID
-	if err := h.warehouseSvc.SaveLocation(&item, orgID); err != nil {
+	if err := h.warehouseSvc.UpdateLocation(&item, orgID); err != nil {
 		response.BadRequest(c, err.Error())
 		return
 	}
diff --git a/internal/service/admin_master.go b/internal/service/admin_master.go
index 14c0332e..21cf1f6f 100644
--- a/internal/service/admin_master.go
+++ b/internal/service/admin_master.go
@@ -251,7 +251,27 @@ func NewWarehouseService() *WarehouseService {
 func (s *WarehouseService) List(orgID int64) ([]model.Warehouse, error) {
 	return s.repo.List(orgID)
 }
-func (s *WarehouseService) Save(item *model.Warehouse) error {
+// Create 新建仓库。不读取 item.ID，脏 id 不会把新建变成覆盖。
+func (s *WarehouseService) Create(item *model.Warehouse) error {
+	if err := prepareWarehouse(item); err != nil {
+		return err
+	}
+	return s.repo.Create(item)
+}
+
+// Update 更新仓库。id 来自路由参数，必须显式存在。
+func (s *WarehouseService) Update(item *model.Warehouse) error {
+	if item.ID == 0 {
+		return errUpdateRequiresID
+	}
+	if err := prepareWarehouse(item); err != nil {
+		return err
+	}
+	return s.repo.Update(item)
+}
+
+// prepareWarehouse 是新建与更新共用的字段清理、校验和默认值补全。
+func prepareWarehouse(item *model.Warehouse) error {
 	item.Code = strings.TrimSpace(item.Code)
 	item.Name = strings.TrimSpace(item.Name)
 	if item.Code == "" || item.Name == "" {
@@ -260,12 +280,30 @@ func (s *WarehouseService) Save(item *model.Warehouse) error {
 	if item.Status == "" {
 		item.Status = "active"
 	}
-	if item.ID == 0 {
-		return s.repo.Create(item)
-	}
-	return s.repo.Update(item)
+	return nil
 }
-func (s *WarehouseService) SaveLocation(item *model.WarehouseLocation, orgID int64) error {
+
+// CreateLocation 新建库位。orgID 用于校验仓库归属，item.ID 不参与。
+func (s *WarehouseService) CreateLocation(item *model.WarehouseLocation, orgID int64) error {
+	if err := prepareLocation(item); err != nil {
+		return err
+	}
+	return s.repo.CreateLocation(item, orgID)
+}
+
+// UpdateLocation 更新库位。id 来自路由参数，必须显式存在。
+func (s *WarehouseService) UpdateLocation(item *model.WarehouseLocation, orgID int64) error {
+	if item.ID == 0 {
+		return errUpdateRequiresID
+	}
+	if err := prepareLocation(item); err != nil {
+		return err
+	}
+	return s.repo.UpdateLocation(item, orgID)
+}
+
+// prepareLocation 是新建与更新共用的字段清理、校验和默认值补全。
+func prepareLocation(item *model.WarehouseLocation) error {
 	item.Code = strings.TrimSpace(item.Code)
 	item.Name = strings.TrimSpace(item.Name)
 	if item.Code == "" || item.Name == "" || item.WarehouseID <= 0 {
@@ -274,8 +312,5 @@ func (s *WarehouseService) SaveLocation(item *model.WarehouseLocation, orgID int
 	if item.Status == "" {
 		item.Status = "active"
 	}
-	if item.ID == 0 {
-		return s.repo.CreateLocation(item, orgID)
-	}
-	return s.repo.UpdateLocation(item, orgID)
+	return nil
 }
diff --git a/internal/service/admin_master_test.go b/internal/service/admin_master_test.go
index 20b74d25..23c91175 100644
--- a/internal/service/admin_master_test.go
+++ b/internal/service/admin_master_test.go
@@ -98,3 +98,36 @@ func TestUnitCreateStillValidatesPrecisionScale(t *testing.T) {
 		t.Fatal("precision_scale 超过 6 应当被拒绝")
 	}
 }
+
+func TestWarehouseCreateInsertsEvenWhenItemCarriesStaleID(t *testing.T) {
+	db, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("sqlmock: %v", err)
+	}
+	database.DB = db
+	t.Cleanup(func() { database.DB = nil; db.Close() })
+
+	mock.ExpectExec("INSERT INTO warehouses").WillReturnResult(sqlmock.NewResult(5, 1))
+
+	item := &model.Warehouse{ID: 3, Code: "WH2", Name: "二号仓"}
+	if err := NewWarehouseService().Create(item); err != nil {
+		t.Fatalf("Create: %v", err)
+	}
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Fatalf("应当执行 INSERT，实际 SQL 不是插入: %v", err)
+	}
+}
+
+func TestWarehouseUpdateRequiresID(t *testing.T) {
+	err := NewWarehouseService().Update(&model.Warehouse{Code: "WH1", Name: "一号仓"})
+	if err == nil {
+		t.Fatal("缺少 id 的更新应当被拒绝")
+	}
+}
+
+func TestLocationCreateRequiresWarehouseID(t *testing.T) {
+	err := NewWarehouseService().CreateLocation(&model.WarehouseLocation{Code: "L1", Name: "库位一"}, 1)
+	if err == nil {
+		t.Fatal("缺少 warehouse_id 的库位创建应当被拒绝")
+	}
+}