diff --git a/backend/src/api/dailyInventory.js b/backend/src/api/dailyInventory.js
new file mode 100644
index 0000000..7bdc9a1
--- /dev/null
+++ b/backend/src/api/dailyInventory.js
@@ -0,0 +1,179 @@
+const express = require('express');
+const cloudDb = require('../config/cloudDatabase');
+const {
+  DAILY_INVENTORY_BASELINE,
+  BASELINE_DATE,
+  FLOW_COLUMNS,
+} = require('../config/dailyInventoryBaseline');
+
+const router = express.Router();
+
+/** 库存衡量基准时刻：快照日次日 01:00（报表库每日凌晨 1 点跑批，标注 T-1） */
+const AS_OF_TIME = '01:00';
+
+const toNumber = (v) => {
+  if (v == null) return null;
+  const n = Number(v);
+  return Number.isFinite(n) ? n : null;
+};
+
+/** 快照日 + 次日 01:00 作为统一的库龄/分级基准 */
+function nextDayAsOf(bizDate) {
+  if (!bizDate || !/^\d{4}-\d{2}-\d{2}$/.test(bizDate)) return null;
+  const d = new Date(`${bizDate}T00:00:00Z`);
+  d.setUTCDate(d.getUTCDate() + 1);
+  return `${d.toISOString().slice(0, 10)} ${AS_OF_TIME}`;
+}
+
+async function fetchLatestBizDate() {
+  const rows = await cloudDb.query(
+    `SELECT MAX(CONVERT(VARCHAR(10), date, 23)) AS d FROM rpt.pm_stockMonitor`
+  );
+  return rows[0]?.d || null;
+}
+
+/**
+ * 派生列（SQL CASE WHEN 下沉计算）
+ * - 库龄(天) = DATEDIFF(asOf, created)
+ * - 库存周转天数 = 月度发货总件数 / 月度日均库存件数 × 100%
+ *   月度发货总件数 = threeAvgSale × 30；月度日均库存件数 = jsStock
+ * - 四级分级：库龄 + 周转率双维度
+ */
+function buildDerivedColumns(asOf) {
+  const A = '@asOf';
+  void A;
+  const ageDays = `DATEDIFF(DAY, m.created, @asOf)`;
+  const turnover = `(ISNULL(m.threeAvgSale, 0) * 30.0 * 100.0 / NULLIF(m.jsStock, 0))`;
+  return {
+    ageDays,
+    turnoverDays: `CAST(${turnover} AS DECIMAL(18, 4))`,
+    levelExpr: `
+      CASE
+        WHEN m.created IS NULL OR ISNULL(m.jsStock, 0) = 0 OR ${turnover} IS NULL THEN NULL
+        WHEN ${ageDays} < 90 AND ${turnover} BETWEEN 30 AND 199 THEN 'warn'
+        WHEN ${ageDays} < 90 AND ${turnover} >= 200 THEN 'slow'
+        WHEN ${ageDays} >= 90 AND ${turnover} BETWEEN 30 AND 99 THEN 'slow'
+        WHEN ${ageDays} BETWEEN 90 AND 365 AND ${turnover} >= 100 THEN 'stale'
+        WHEN ${ageDays} > 365 AND ${turnover} BETWEEN 100 AND 199 THEN 'stale'
+        WHEN ${ageDays} > 365 AND ${turnover} >= 200 THEN 'zombie'
+        ELSE NULL
+      END`,
+  };
+}
+
+/** 该仓快照里的四级库存量与平均周转天数 */
+async function fetchGradeMetrics(dbWarehouse, bizDate, asOf) {
+  const D = buildDerivedColumns(asOf);
+  const rows = await cloudDb.query(
+    `SELECT COUNT(*) AS skuCount,
+            SUM(CAST(ISNULL(m.jsStock, 0) AS DECIMAL(18, 2))) AS gradeStock,
+            AVG(${D.turnoverDays}) AS avgTurnover,
+            SUM(CASE WHEN ${D.levelExpr} = 'warn' THEN CAST(ISNULL(m.jsStock, 0) AS DECIMAL(18, 2)) ELSE 0 END) AS warnLevel,
+            SUM(CASE WHEN ${D.levelExpr} = 'slow' THEN CAST(ISNULL(m.jsStock, 0) AS DECIMAL(18, 2)) ELSE 0 END) AS slowLevel,
+            SUM(CASE WHEN ${D.levelExpr} = 'stale' THEN CAST(ISNULL(m.jsStock, 0) AS DECIMAL(18, 2)) ELSE 0 END) AS staleLevel,
+            SUM(CASE WHEN ${D.levelExpr} = 'zombie' THEN CAST(ISNULL(m.jsStock, 0) AS DECIMAL(18, 2)) ELSE 0 END) AS zombieLevel
+       FROM rpt.pm_stockMonitor m
+      WHERE m.warehouse = @warehouse
+        AND CONVERT(VARCHAR(10), m.date, 23) = @bizDate`,
+    { warehouse: dbWarehouse, bizDate, asOf }
+  );
+  const r = rows[0] || {};
+  if (!Number(r.skuCount || 0)) return null;
+  return {
+    skuCount: toNumber(r.skuCount),
+    gradeStock: toNumber(r.gradeStock),
+    turnoverDays: toNumber(r.avgTurnover),
+    warnLevel: toNumber(r.warnLevel),
+    slowLevel: toNumber(r.slowLevel),
+    staleLevel: toNumber(r.staleLevel),
+    zombieLevel: toNumber(r.zombieLevel),
+  };
+}
+
+/** 实时期末库存（单仓 wms_co_id），并带回最近更新时间便于核对时效 */
+async function fetchClosingQty(wmsCoId) {
+  if (wmsCoId == null) return null;
+  const rows = await cloudDb.query(
+    `SELECT ISNULL(SUM(CAST(qty AS DECIMAL(18, 2))), 0) AS qty,
+            COUNT(CASE WHEN ISNULL(qty, 0) <> 0 THEN 1 END) AS skuCount,
+            MAX(modified) AS takenAt
+       FROM rpt.jst_inventoryInfo
+      WHERE wms_co_id = @wmsCoId`,
+    { wmsCoId }
+  );
+  const r = rows[0] || {};
+  return {
+    closingQty: toNumber(r.qty),
+    closingSkuCount: toNumber(r.skuCount) || 0,
+    closingTakenAt: r.takenAt || null,
+  };
+}
+
+/**
+ * GET /api/daily-inventory
+ * 每日进销存：25 个仓库 × 进销存流水 + 期末 + 分级库存量
+ *
+ * 数据源分工：
+ *   - 期初数量 与 12 个流水列：22 号基准（dailyInventoryBaseline.js）
+ *   - 期末数量：jst_inventoryInfo 实时库存
+ *   - 库存周转天数 / 四级库存量：pm_stockMonitor 快照
+ */
+router.get('/', async (req, res) => {
+  try {
+    const latestBizDate = await fetchLatestBizDate().catch(() => null);
+    const asOf = nextDayAsOf(latestBizDate);
+
+    const items = [];
+    for (const base of DAILY_INVENTORY_BASELINE) {
+      const flows = {};
+      for (const col of FLOW_COLUMNS) flows[col.field] = base[col.field] ?? 0;
+
+      const closing = await fetchClosingQty(base.wmsCoId).catch(() => null);
+      const grade = base.dbWarehouse && latestBizDate
+        ? await fetchGradeMetrics(base.dbWarehouse, latestBizDate, asOf).catch(() => null)
+        : null;
+
+      items.push({
+        warehouse: base.warehouse,
+        dbWarehouse: base.dbWarehouse,
+        openingQty: base.openingQty,
+        openingQtyExtra: base.openingQtyExtra,
+        ...flows,
+        closingQty: closing?.closingQty ?? null,
+        closingSkuCount: closing?.closingSkuCount ?? null,
+        closingTakenAt: closing?.closingTakenAt ?? null,
+        turnoverDays: grade?.turnoverDays ?? null,
+        gradeStock: grade?.gradeStock ?? null,
+        warnLevel: grade?.warnLevel ?? null,
+        slowLevel: grade?.slowLevel ?? null,
+        staleLevel: grade?.staleLevel ?? null,
+        zombieLevel: grade?.zombieLevel ?? null,
+        hasGrade: Boolean(grade),
+      });
+    }
+
+    // 合计行：便于与表格总额核对
+    const sum = (k) => items.reduce((acc, it) => acc + (Number(it[k]) || 0), 0);
+    const totals = { warehouse: '合计', dbWarehouse: '', isTotal: true };
+    for (const k of ['openingQty', 'openingQtyExtra', ...FLOW_COLUMNS.map((c) => c.field), 'closingQty', 'warnLevel', 'slowLevel', 'staleLevel', 'zombieLevel']) {
+      totals[k] = Number(sum(k).toFixed(2));
+    }
+
+    res.json({
+      success: true,
+      data: {
+        baselineDate: BASELINE_DATE,
+        latestBizDate,
+        asOf,
+        flowColumns: FLOW_COLUMNS,
+        items,
+        totals,
+      },
+    });
+  } catch (error) {
+    console.error('[daily-inventory] 查询失败:', error.message);
+    res.status(500).json({ success: false, error: '每日进销存数据查询失败', detail: error.message });
+  }
+});
+
+module.exports = router;