diff --git a/backend/src/services/modularStockMonitorService.js b/backend/src/services/modularStockMonitorService.js
index 1718467..affb51f 100644
--- a/backend/src/services/modularStockMonitorService.js
+++ b/backend/src/services/modularStockMonitorService.js
@@ -13,6 +13,8 @@
 //         目标仓库共 794 个 SKU
 //   库存  rpt.jst_inventoryInfo  —— 实时库存 qty；按 wms_co_id 区分仓库
 //         目标仓库 wms_co_id = 15718196（rpt.jst_warehouseInfo 查得）
+//         该表为 0/缺行而箱及仓位库存已有正库存时，用同仓 rpt.jst_packInventoryInfo 合计补齐；
+//         只补 0，不覆盖 inventoryInfo 中的正库存，避免箱表未覆盖散货时低估库存。
 //   监控  rpt.pm_stockMonitor    —— 日更快照，目标仓每天 794 行，覆盖全部 SKU：
 //         fifteenAvgSale 近15天日均发货量（2026-09-17 由 7 天改 15 天，见下）
 //         jsUseDays     库存可用天数
@@ -77,13 +79,39 @@ const SORTABLE_FIELDS = Object.freeze({
   category: 's.category',
   realtimeStock: 'realtimeStock',
   avgShip15d: 'm.fifteenAvgSale',
-  stockDays: 'm.jsUseDays',
+  stockDays: 'stockDays',
   warningLevel: 'warningOrder',
   mkhStatus: 'mkhStatus',
   location: 'location',
   warehouse: 's.other_3',
 });
 
+// 实时库存优先使用库存表；库存表没有正库存时，用同仓「箱及仓位库存」补齐。
+// 聚水潭上游可能已经生成箱/仓位库存，但 jst_inventoryInfo 仍停留在旧值。
+// 只补 0/缺行，避免箱表只记录部分装箱库存时压低库存表中的有效库存。
+const buildRealtimeStockSql = () => (
+  `CASE
+     WHEN inv.qty > 0 THEN inv.qty
+     WHEN ISNULL(ploc.packQty, 0) > 0 THEN ploc.packQty
+     WHEN inv.qty IS NOT NULL THEN inv.qty
+     ELSE ISNULL(m.jsStock, 0)
+   END`
+);
+
+// 箱表兜底生效时，监控快照的 jsUseDays 仍基于旧库存，需要同步重算。
+// 无日销时返回 NULL，不能因为旧快照为 0 天而把已有库存误报为低库存。
+const buildStockDaysSql = () => (
+  `CASE
+     WHEN ISNULL(inv.qty, 0) <= 0 AND ISNULL(ploc.packQty, 0) > 0 THEN
+       CASE
+         WHEN ISNULL(m.fifteenAvgSale, 0) > 0
+           THEN CAST(ploc.packQty / NULLIF(m.fifteenAvgSale, 0) AS DECIMAL(18, 2))
+         ELSE NULL
+       END
+     ELSE m.jsUseDays
+   END`
+);
+
 /**
  * 「已配置MKH」判定表达式（2026-09-17 晚修正口径）：
  *   该 SKU 作为「配件商品编码」（map_outer_sku_id）出现在聚水潭 SKU 级 BOM 维护
@@ -107,8 +135,9 @@ const buildConfiguredExistsSql = () => (
 const buildWarningOrderSql = () => (
   `CASE
      WHEN cfg.configured = 0 THEN 2
-     WHEN COALESCE(inv.qty, m.jsStock, 0) <= 0 THEN 0
-     WHEN m.jsUseDays IS NOT NULL AND m.jsUseDays <= ${LOW_STOCK_DAYS_THRESHOLD} THEN 1
+     WHEN ${buildRealtimeStockSql()} <= 0 THEN 0
+     WHEN ${buildStockDaysSql()} IS NOT NULL
+       AND ${buildStockDaysSql()} <= ${LOW_STOCK_DAYS_THRESHOLD} THEN 1
      ELSE 2
    END`
 );
@@ -171,15 +200,29 @@ OUTER APPLY (
   WHERE UPPER(LTRIM(RTRIM(TRY_CONVERT(NVARCHAR(100), c.sku)))) = UPPER(LTRIM(RTRIM(TRY_CONVERT(NVARCHAR(100), s.sku_id))))
   ORDER BY c.createTime DESC
 ) cost
--- 仓位：主货位（真货位），见 buildLocationSql() 说明
-OUTER APPLY (
-  SELECT TOP 1 NULLIF(LTRIM(RTRIM(pk.bin)), N'') AS bin
-  FROM dbo.jst_packInventoryInfo pk WITH (NOLOCK)
-  WHERE pk.sku_id = s.sku_id
-    AND NULLIF(LTRIM(RTRIM(pk.bin)), N'') IS NOT NULL
-    AND ISNULL(pk.qty, 0) > 0
-  ORDER BY pk.qty DESC
-) ploc
+-- 仓位及箱库存：先按 SKU/仓位一次性汇总，再关联目标仓，避免对 794 个 SKU
+-- 分别扫描无独立索引的上游视图。rn=1 是库存最大的主货位，packQty 是该 SKU 全仓合计。
+LEFT JOIN (
+  SELECT ranked.sku_id, ranked.wms_co_id, ranked.bin, ranked.packQty
+  FROM (
+    SELECT
+      pk.sku_id,
+      pk.wms_co_id,
+      NULLIF(LTRIM(RTRIM(pk.bin)), N'') AS bin,
+      SUM(ISNULL(pk.qty, 0)) AS binQty,
+      SUM(SUM(ISNULL(pk.qty, 0))) OVER (PARTITION BY pk.sku_id, pk.wms_co_id) AS packQty,
+      ROW_NUMBER() OVER (
+        PARTITION BY pk.sku_id, pk.wms_co_id
+        ORDER BY SUM(ISNULL(pk.qty, 0)) DESC, NULLIF(LTRIM(RTRIM(pk.bin)), N'') ASC
+      ) AS rn
+    FROM dbo.jst_packInventoryInfo pk WITH (NOLOCK)
+    WHERE pk.wms_co_id = @wmsCoId
+      AND NULLIF(LTRIM(RTRIM(pk.bin)), N'') IS NOT NULL
+    GROUP BY pk.sku_id, pk.wms_co_id, NULLIF(LTRIM(RTRIM(pk.bin)), N'')
+    HAVING SUM(ISNULL(pk.qty, 0)) > 0
+  ) ranked
+  WHERE ranked.rn = 1
+) ploc ON ploc.sku_id = s.sku_id AND ploc.wms_co_id = @wmsCoId
 -- 模块化配置状态：见文件头部「已配置MKH」口径说明
 OUTER APPLY (
   SELECT CAST(CASE WHEN ${buildConfiguredExistsSql()} THEN 1 ELSE 0 END AS BIT) AS configured
@@ -362,13 +405,13 @@ const buildProjection = () => `
   s.sku_id                                                                        AS skuId,
   s.name                                                                          AS productName,
   s.category                                                                      AS category,
-  COALESCE(inv.qty, m.jsStock, 0)                                                 AS realtimeStock,
+  ${buildRealtimeStockSql()}                                                     AS realtimeStock,
   ISNULL(ptr.transit, 0)                                                          AS purchaseTransit,
   ISNULL(pin.inQty, 0)                                                            AS inQtyToday,
   ISNULL(m.nearSecondSale, 0)                                                     AS outQtyToday,
   ${buildLocationSql()}                                                           AS location,
   m.fifteenAvgSale                                                                AS avgShip15d,
-  m.jsUseDays                                                                     AS stockDays,
+  ${buildStockDaysSql()}                                                          AS stockDays,
   m.safetyDays                                                                    AS safetyDays,
   m.suggestStock                                                                  AS suggestStock,
   s.other_3                                                                       AS warehouse,
@@ -445,7 +488,7 @@ async function buildSummary(whereSql, params) {
     `SELECT
        COUNT_BIG(*)                                                                   AS skuCount,
        SUM(CASE WHEN ${buildWarningOrderSql()} = 0 THEN 1 ELSE 0 END)                          AS outOfStockCount,
-       CAST(ISNULL(SUM(COALESCE(inv.qty, m.jsStock, 0)), 0) AS BIGINT)                             AS totalStock,
+       CAST(ISNULL(SUM(${buildRealtimeStockSql()}), 0) AS BIGINT)                                  AS totalStock,
        CAST(ISNULL(SUM(ISNULL(ptr.transit, 0)), 0) AS BIGINT)                                   AS totalPurchaseTransit,
        SUM(CASE WHEN ${buildWarningOrderSql()} = 1 THEN 1 ELSE 0 END)                          AS lowStockDaysCount,
        SUM(CASE WHEN cfg.configured = 1 THEN 1 ELSE 0 END)                                       AS configuredCount,
diff --git a/frontend/src/pages/ModularStockMonitor/index.jsx b/frontend/src/pages/ModularStockMonitor/index.jsx
index ec08b52..dd3c9a2 100644
--- a/frontend/src/pages/ModularStockMonitor/index.jsx
+++ b/frontend/src/pages/ModularStockMonitor/index.jsx
@@ -271,7 +271,10 @@ const AccessoryStockPanel = () => {
         : int(value)),
     },
     {
-      title: '实时库存',
+      title: <TipTitle
+        title="实时库存"
+        tip="优先取目标仓 jst_inventoryInfo；该表为 0 或缺少记录、但箱及仓位库存已有正库存时，用同仓 jst_packInventoryInfo 合计补齐"
+      />,
       dataIndex: 'realtimeStock',
       width: 96,
       align: 'right',
@@ -281,7 +284,7 @@ const AccessoryStockPanel = () => {
     {
       title: <TipTitle
         title="采购在途数量"
-        tip="该商品（配件）全部采购单中『已下单 − 已入库』的未到货数量合计，取自 jst_purchaseItem.qty − inQty"
+        tip="采购单中『已下单 − 已入库』的数量，取自 jst_purchaseItem.qty − inQty；它与实时库存独立，上游采购到货字段滞后时可能同时显示库存和在途"
       />,
       dataIndex: 'purchaseTransit',
       width: 120,