diff --git a/backend/internal/handler/stock_cost_confirm_test.go b/backend/internal/handler/stock_cost_confirm_test.go
new file mode 100644
index 0000000..e35b888
--- /dev/null
+++ b/backend/internal/handler/stock_cost_confirm_test.go
@@ -0,0 +1,191 @@
+package handler
+
+import (
+	"fmt"
+	"net/http"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/wangjia/jiu/backend/internal/model"
+	"github.com/wangjia/jiu/backend/testutil"
+)
+
+// 调货核心场景：0 价入库 → 审核 → 部分出库 → 确认进价（前向补偿）。
+func TestConfirmCost_BackfillsCostAndAdjustsPayable(t *testing.T) {
+	db := testutil.SetupTestDB()
+	shop := testutil.CreateTestShop(db, "CC_MAIN")
+	admin := testutil.CreateTestUser(db, shop.ID, "admin", "pass", "admin")
+	wh := testutil.CreateTestWarehouse(db, shop.ID, "仓")
+	prod := testutil.CreateTestProduct(db, shop.ID, "茅台")
+	adminToken := getAuthToken(admin.ID, shop.ID, "admin")
+	r := setupProtectedRouter(db)
+
+	// 0 价入库 10 → 审核
+	w := makeRequest(r, "POST", "/api/v1/stock-in/orders", adminToken, map[string]interface{}{
+		"warehouse_id": wh.ID, "order_date": time.Now().Format(time.RFC3339),
+		"items": []map[string]interface{}{{"product_id": prod.ID, "quantity": 10.0, "unit_price": 0.0}},
+	})
+	require.Equal(t, http.StatusCreated, w.Code)
+	inID := extractID(w)
+	makeRequest(r, "PUT", fmt.Sprintf("/api/v1/stock-in/orders/%d/submit", inID), adminToken, nil)
+	makeRequest(r, "PUT", fmt.Sprintf("/api/v1/stock-in/orders/%d/approve", inID), adminToken, nil)
+
+	var inItem model.StockInItem
+	require.NoError(t, db.Where("order_id = ?", inID).First(&inItem).Error)
+	pid := inItem.ProductID // 序列号模型：入库为该行新建独立 product
+
+	// 库存批次成本待定（UnitPrice 为 NULL）
+	var inv model.Inventory
+	require.NoError(t, db.Where("shop_id = ? AND stock_in_item_id = ?", shop.ID, inItem.ID).First(&inv).Error)
+	assert.Nil(t, inv.UnitPrice, "0 价入库时库存成本应为待定(NULL)")
+
+	// 出库 4（售价 80，成本暂为 0）→ 审核
+	w = makeRequest(r, "POST", "/api/v1/stock-out/orders", adminToken, map[string]interface{}{
+		"warehouse_id": wh.ID, "order_date": time.Now().Format(time.RFC3339),
+		"items": []map[string]interface{}{{"product_id": pid, "quantity": 4.0, "unit_price": 0.0, "sale_price": 80.0}},
+	})
+	outID := extractID(w)
+	makeRequest(r, "PUT", fmt.Sprintf("/api/v1/stock-out/orders/%d/submit", outID), adminToken, nil)
+	makeRequest(r, "PUT", fmt.Sprintf("/api/v1/stock-out/orders/%d/approve", outID), adminToken, nil)
+
+	// 确认进价 50
+	w = makeRequest(r, "POST", fmt.Sprintf("/api/v1/stock-in/orders/%d/confirm-cost", inID), adminToken,
+		map[string]interface{}{"items": []map[string]interface{}{{"item_id": inItem.ID, "unit_price": 50.0}}})
+	require.Equal(t, http.StatusOK, w.Code)
+
+	// 1. 入库明细成本回填
+	db.First(&inItem, inItem.ID)
+	assert.Equal(t, 50.0, inItem.UnitPrice)
+	assert.Equal(t, 500.0, inItem.TotalPrice)
+
+	// 2. 剩余库存批次成本回填（6 件）
+	db.First(&inv, inv.ID)
+	require.NotNil(t, inv.UnitPrice)
+	assert.Equal(t, 50.0, *inv.UnitPrice)
+
+	// 3. 已出库行成本快照回填，售价/应收不变
+	var outItem model.StockOutItem
+	require.NoError(t, db.Where("order_id = ?", outID).First(&outItem).Error)
+	assert.Equal(t, 50.0, outItem.UnitPrice, "已出库成本应回填")
+	assert.Equal(t, 200.0, outItem.TotalPrice, "成本小计 = 50×4")
+	assert.Equal(t, 80.0, outItem.SalePrice, "售价不应被改动")
+
+	var outOrder model.StockOutOrder
+	db.First(&outOrder, outID)
+	assert.Equal(t, 320.0, outOrder.TotalAmount, "应收按售价 4×80，确认进价不影响")
+
+	// 4. 入库单总额按差额重算：0 → 500
+	var inOrder model.StockInOrder
+	db.First(&inOrder, inID)
+	assert.Equal(t, 500.0, inOrder.TotalAmount)
+
+	// 5. 应付差额调整流水：+500（balance 是应收应付混合滚动总账：0 入 + 320 应收 + 500 = 820）
+	var adj model.FinanceRecord
+	require.NoError(t, db.Where("shop_id = ? AND type = 'payable' AND ref_type = 'stock_in_cost_adjust'", shop.ID).
+		First(&adj).Error)
+	assert.Equal(t, 500.0, adj.Amount)
+	assert.Equal(t, 820.0, adj.Balance)
+
+	// 6. product 参考进价同步（pid 是入库新建的独立 product）
+	var p2 model.Product
+	require.NoError(t, db.First(&p2, pid).Error)
+	assert.Equal(t, 50.0, p2.PurchasePrice)
+}
+
+// 非管理员无权确认进价。
+func TestConfirmCost_Forbidden(t *testing.T) {
+	db := testutil.SetupTestDB()
+	shop := testutil.CreateTestShop(db, "CC_FORBID")
+	admin := testutil.CreateTestUser(db, shop.ID, "admin", "pass", "admin")
+	op := testutil.CreateTestUser(db, shop.ID, "op", "pass", "operator")
+	wh := testutil.CreateTestWarehouse(db, shop.ID, "仓")
+	prod := testutil.CreateTestProduct(db, shop.ID, "五粮液")
+	adminToken := getAuthToken(admin.ID, shop.ID, "admin")
+	opToken := getAuthToken(op.ID, shop.ID, "operator")
+	r := setupProtectedRouter(db)
+
+	w := makeRequest(r, "POST", "/api/v1/stock-in/orders", adminToken, map[string]interface{}{
+		"warehouse_id": wh.ID, "order_date": time.Now().Format(time.RFC3339),
+		"items": []map[string]interface{}{{"product_id": prod.ID, "quantity": 5.0, "unit_price": 0.0}},
+	})
+	inID := extractID(w)
+	makeRequest(r, "PUT", fmt.Sprintf("/api/v1/stock-in/orders/%d/submit", inID), adminToken, nil)
+	makeRequest(r, "PUT", fmt.Sprintf("/api/v1/stock-in/orders/%d/approve", inID), adminToken, nil)
+	var inItem model.StockInItem
+	db.Where("order_id = ?", inID).First(&inItem)
+
+	w = makeRequest(r, "POST", fmt.Sprintf("/api/v1/stock-in/orders/%d/confirm-cost", inID), opToken,
+		map[string]interface{}{"items": []map[string]interface{}{{"item_id": inItem.ID, "unit_price": 30.0}}})
+	assert.Equal(t, http.StatusForbidden, w.Code)
+}
+
+// 仅 approved 单可确认；草稿/待审核拒绝。
+func TestConfirmCost_RejectsNonApproved(t *testing.T) {
+	db := testutil.SetupTestDB()
+	shop := testutil.CreateTestShop(db, "CC_DRAFT")
+	admin := testutil.CreateTestUser(db, shop.ID, "admin", "pass", "admin")
+	wh := testutil.CreateTestWarehouse(db, shop.ID, "仓")
+	prod := testutil.CreateTestProduct(db, shop.ID, "汾酒")
+	adminToken := getAuthToken(admin.ID, shop.ID, "admin")
+	r := setupProtectedRouter(db)
+
+	w := makeRequest(r, "POST", "/api/v1/stock-in/orders", adminToken, map[string]interface{}{
+		"warehouse_id": wh.ID, "order_date": time.Now().Format(time.RFC3339),
+		"items": []map[string]interface{}{{"product_id": prod.ID, "quantity": 5.0, "unit_price": 0.0}},
+	})
+	inID := extractID(w)
+	var inItem model.StockInItem
+	db.Where("order_id = ?", inID).First(&inItem)
+
+	// 仍是 draft → 400
+	w = makeRequest(r, "POST", fmt.Sprintf("/api/v1/stock-in/orders/%d/confirm-cost", inID), adminToken,
+		map[string]interface{}{"items": []map[string]interface{}{{"item_id": inItem.ID, "unit_price": 30.0}}})
+	assert.Equal(t, http.StatusBadRequest, w.Code)
+}
+
+// 重复确认：按新旧差额增量补偿，不重复全量。
+func TestConfirmCost_RepeatableByDiff(t *testing.T) {
+	db := testutil.SetupTestDB()
+	shop := testutil.CreateTestShop(db, "CC_REPEAT")
+	admin := testutil.CreateTestUser(db, shop.ID, "admin", "pass", "admin")
+	wh := testutil.CreateTestWarehouse(db, shop.ID, "仓")
+	prod := testutil.CreateTestProduct(db, shop.ID, "剑南春")
+	adminToken := getAuthToken(admin.ID, shop.ID, "admin")
+	r := setupProtectedRouter(db)
+
+	w := makeRequest(r, "POST", "/api/v1/stock-in/orders", adminToken, map[string]interface{}{
+		"warehouse_id": wh.ID, "order_date": time.Now().Format(time.RFC3339),
+		"items": []map[string]interface{}{{"product_id": prod.ID, "quantity": 10.0, "unit_price": 0.0}},
+	})
+	inID := extractID(w)
+	makeRequest(r, "PUT", fmt.Sprintf("/api/v1/stock-in/orders/%d/submit", inID), adminToken, nil)
+	makeRequest(r, "PUT", fmt.Sprintf("/api/v1/stock-in/orders/%d/approve", inID), adminToken, nil)
+	var inItem model.StockInItem
+	db.Where("order_id = ?", inID).First(&inItem)
+
+	// 第一次确认 50（diff 500）
+	makeRequest(r, "POST", fmt.Sprintf("/api/v1/stock-in/orders/%d/confirm-cost", inID), adminToken,
+		map[string]interface{}{"items": []map[string]interface{}{{"item_id": inItem.ID, "unit_price": 50.0}}})
+	// 第二次修正为 60（diff 100）
+	w = makeRequest(r, "POST", fmt.Sprintf("/api/v1/stock-in/orders/%d/confirm-cost", inID), adminToken,
+		map[string]interface{}{"items": []map[string]interface{}{{"item_id": inItem.ID, "unit_price": 60.0}}})
+	require.Equal(t, http.StatusOK, w.Code)
+
+	db.First(&inItem, inItem.ID)
+	assert.Equal(t, 60.0, inItem.UnitPrice)
+
+	var inOrder model.StockInOrder
+	db.First(&inOrder, inID)
+	assert.Equal(t, 600.0, inOrder.TotalAmount, "总额 = 60×10")
+
+	// 两条调整流水：+500 与 +100，余额滚动到 600
+	var adjs []model.FinanceRecord
+	db.Where("shop_id = ? AND ref_type = 'stock_in_cost_adjust'", shop.ID).Order("id ASC").Find(&adjs)
+	require.Len(t, adjs, 2)
+	assert.Equal(t, 500.0, adjs[0].Amount)
+	assert.Equal(t, 100.0, adjs[1].Amount)
+	assert.Equal(t, 600.0, adjs[1].Balance)
+}
diff --git a/backend/internal/handler/stock_in.go b/backend/internal/handler/stock_in.go
index 6416762..b96ad8d 100644
--- a/backend/internal/handler/stock_in.go
+++ b/backend/internal/handler/stock_in.go
@@ -315,3 +315,41 @@ func (h *StockInHandler) Return(c *gin.Context) {
 	}
 	c.JSON(http.StatusOK, gin.H{"message": "returned"})
 }
+
+// ConfirmCost POST /api/v1/stock-in/orders/:id/confirm-cost
+// 确认进价：调货等以 0 价（暂估）入库并已审核后，价格确定时补填真实进价。
+// 前向补偿（更新库存成本、回填已出库成本快照、补应付差额），不反审核。
+// 仅 approved 单、管理员/超管（service 内判权）。
+func (h *StockInHandler) ConfirmCost(c *gin.Context) {
+	shopID := middleware.GetShopID(c)
+	userID := middleware.GetUserID(c)
+	role := middleware.GetRole(c)
+	id, _ := strconv.ParseUint(c.Param("id"), 10, 64)
+
+	var req struct {
+		Items []service.CostConfirmItem `json:"items"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+	if len(req.Items) == 0 {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "未提供要确认的明细"})
+		return
+	}
+	for _, it := range req.Items {
+		if it.UnitPrice <= 0 {
+			c.JSON(http.StatusBadRequest, gin.H{"error": "进价必须大于 0"})
+			return
+		}
+	}
+	if err := h.stockSvc.ConfirmStockInCost(shopID, id, userID, role, req.Items); err != nil {
+		if errors.Is(err, service.ErrForbidden) {
+			c.JSON(http.StatusForbidden, gin.H{"error": "无权确认进价"})
+			return
+		}
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"message": "cost confirmed"})
+}
diff --git a/backend/internal/handler/testhelper_test.go b/backend/internal/handler/testhelper_test.go
index 25f2c58..1a03065 100644
--- a/backend/internal/handler/testhelper_test.go
+++ b/backend/internal/handler/testhelper_test.go
@@ -66,6 +66,7 @@ func setupProtectedRouter(db *gorm.DB) *gin.Engine {
 	stockIn.PUT("/orders/:id/reject", stockInH.Reject)
 	stockIn.PUT("/orders/:id/withdraw", stockInH.Withdraw)
 	stockIn.POST("/orders/:id/return", stockInH.Return)
+	stockIn.POST("/orders/:id/confirm-cost", stockInH.ConfirmCost)
 
 	// 出库路由
 	stockOut := api.Group("/stock-out")
diff --git a/backend/internal/router/router.go b/backend/internal/router/router.go
index 4622f14..d7a1923 100644
--- a/backend/internal/router/router.go
+++ b/backend/internal/router/router.go
@@ -157,6 +157,8 @@ func Setup(r *gin.Engine, db *gorm.DB) {
 			stockIn.PUT("/orders/:id/withdraw", stockInH.Withdraw)
 			// 退单（已审核单退货，库存删除+冲应付）：仅管理员/超管（service 内判权）
 			stockIn.POST("/orders/:id/return", stockInH.Return)
+			// 确认进价（暂估0价→真实价，前向补偿）：仅管理员/超管（service 内判权）
+			stockIn.POST("/orders/:id/confirm-cost", stockInH.ConfirmCost)
 		}
 
 		// 出库
diff --git a/backend/internal/service/stock.go b/backend/internal/service/stock.go
index 940522f..5f48770 100644
--- a/backend/internal/service/stock.go
+++ b/backend/internal/service/stock.go
@@ -157,6 +157,111 @@ func (s *StockService) ApproveStockIn(shopID, orderID, reviewerID uint64) error
 	})
 }
 
+// CostConfirmItem 是「确认进价」的单行入参：把某入库明细的进价补成真实值。
+type CostConfirmItem struct {
+	ItemID    uint64  `json:"item_id"`
+	UnitPrice float64 `json:"unit_price"`
+}
+
+// ConfirmStockInCost 「确认进价」：调货等场景以 0 价（暂估）入库并已审核/已出库后，
+// 价格确定时补填真实进价。不反审核、不撤销任何已发生的动作，而是在一个事务内
+// 前向写补偿：
+//  1. 入库明细 UnitPrice / TotalPrice 改为真实值
+//  2. 该明细对应的剩余库存批次 Inventory.UnitPrice 由 NULL→真实值
+//  3. 该 product 已出库行 StockOutItem.UnitPrice/TotalPrice（成本快照）回填真实值
+//     （product↔入库明细 1:1，按 product_id 精确命中；不动 SalePrice/应收）
+//  4. 入库单 TotalAmount 按差额重算
+//  5. 对供应商应付按差额补一条调整流水（滚动余额）
+//
+// 仅 approved 单可确认（draft 直接编辑即可）；权限：管理员/超管。
+// 以「旧价→新价」差额计算补偿，支持多次修正（再次确认按新旧差额补）。
+func (s *StockService) ConfirmStockInCost(shopID, orderID, userID uint64, role string, items []CostConfirmItem) error {
+	if role != "admin" && role != "superadmin" {
+		return ErrForbidden
+	}
+	return s.db.Transaction(func(tx *gorm.DB) error {
+		var order model.StockInOrder
+		if err := tx.Preload("Items").Where("id = ? AND shop_id = ?", orderID, shopID).
+			First(&order).Error; err != nil {
+			return err
+		}
+		if order.Status != "approved" {
+			return errors.New("只有已审核单据可确认进价")
+		}
+
+		want := make(map[uint64]float64, len(items))
+		for _, it := range items {
+			want[it.ItemID] = it.UnitPrice
+		}
+
+		now := time.Now()
+		var totalDiff float64
+
+		for i := range order.Items {
+			it := &order.Items[i]
+			newPrice, ok := want[it.ID]
+			if !ok || newPrice == it.UnitPrice {
+				continue
+			}
+			oldPrice := it.UnitPrice
+			diff := (newPrice - oldPrice) * it.Quantity
+			totalDiff += diff
+
+			// 1. 入库明细
+			if err := tx.Model(it).Updates(map[string]interface{}{
+				"unit_price":  newPrice,
+				"total_price": newPrice * it.Quantity,
+			}).Error; err != nil {
+				return err
+			}
+
+			// 2. 该明细的剩余库存批次（已全部出库则无行，跳过）
+			if err := tx.Model(&model.Inventory{}).
+				Where("shop_id = ? AND stock_in_item_id = ? AND deleted_at IS NULL", shopID, it.ID).
+				Update("unit_price", newPrice).Error; err != nil {
+				return err
+			}
+
+			// 3. 已出库行成本快照回填（按 product_id 精确命中；product_id=0 的历史导入单不传播）
+			if it.ProductID != 0 {
+				if err := tx.Model(&model.StockOutItem{}).
+					Where("shop_id = ? AND product_id = ?", shopID, it.ProductID).
+					Updates(map[string]interface{}{
+						"unit_price":  newPrice,
+						"total_price": gorm.Expr("? * quantity", newPrice),
+					}).Error; err != nil {
+					return err
+				}
+			}
+
+			// 同步 product 参考进价
+			if it.ProductID != 0 {
+				tx.Model(&model.Product{}).Where("id = ? AND shop_id = ?", it.ProductID, shopID).
+					Update("purchase_price", newPrice)
+			}
+		}
+
+		if totalDiff == 0 {
+			return nil
+		}
+
+		// 4. 入库单总额按差额重算
+		if err := tx.Model(&order).
+			Update("total_amount", gorm.Expr("total_amount + ?", totalDiff)).Error; err != nil {
+			return err
+		}
+
+		// 5. 应付差额调整流水（滚动余额）
+		bal := partnerLastBalance(tx, shopID, order.PartnerID) + totalDiff
+		oid := order.ID
+		return tx.Create(&model.FinanceRecord{
+			ShopID: shopID, PartnerID: order.PartnerID, Type: "payable",
+			Amount: totalDiff, Balance: bal, Status: "open",
+			RefType: "stock_in_cost_adjust", RefID: &oid, OperatorID: userID, RecordDate: now,
+		}).Error
+	})
+}
+
 // ApproveStockOut 审核出库单，FIFO 扣减批次库存
 func (s *StockService) ApproveStockOut(shopID, orderID, reviewerID uint64) error {
 	return s.db.Transaction(func(tx *gorm.DB) error {