diff --git a/docs/bi-refactor-roadmap.md b/docs/bi-refactor-roadmap.md
index c6db161..2fdad00 100644
--- a/docs/bi-refactor-roadmap.md
+++ b/docs/bi-refactor-roadmap.md
@@ -162,6 +162,7 @@ SUM(fee) / NULLIF(SUM(kwh), 0)
 
 - 已完成电能数据截至时间和实际趋势月展示。
 - 已完成氢能结构化故障状态与重试体验。
+- 已完成里程今日仪表快照复用：普通查询命中分钟级快照，手动刷新生成一致的分页快照。
 - 待恢复氢能数据库后进行总览、站点、客户三层对账。
 - 待 ETC 同步后进行通行记录、账单和收款三层对账。
 
diff --git a/src/modules/mileage/MonitoringView.tsx b/src/modules/mileage/MonitoringView.tsx
index 8890c2f..adae5bc 100644
--- a/src/modules/mileage/MonitoringView.tsx
+++ b/src/modules/mileage/MonitoringView.tsx
@@ -565,7 +565,7 @@ export default function MonitoringView() {
   }, [filterTargetNames]);
 
   // 加载首页数据
-  const loadFirstPage = useCallback((showPageLoading = true) => {
+  const loadFirstPage = useCallback((showPageLoading = true, force = false) => {
     if (showPageLoading) setPageLoading(true);
     setPageError(null);
     return fetchMonitoring({
@@ -589,6 +589,7 @@ export default function MonitoringView() {
       endDate: rangeEnd || undefined,
       brands: filterBrands.length > 0 ? filterBrands : undefined,
       sourcePriority,
+      force,
     }).then(d => {
       setVehicles(d.vehicles);
       setStats(d.stats);
@@ -613,7 +614,7 @@ export default function MonitoringView() {
     if (manualRefreshing) return;
     setManualRefreshing(true);
     try {
-      await loadFirstPage(false);
+      await loadFirstPage(false, true);
     } finally {
       setManualRefreshing(false);
     }
diff --git a/src/modules/mileage/api.ts b/src/modules/mileage/api.ts
index f557f94..ec486b0 100644
--- a/src/modules/mileage/api.ts
+++ b/src/modules/mileage/api.ts
@@ -44,6 +44,7 @@ export async function fetchMonitoring(params?: {
   endDate?: string;
   brands?: string[];
   sourcePriority?: MileageSourceGroup[];
+  force?: boolean;
 }): Promise<MonitoringData> {
   const query = new URLSearchParams();
   if (params?.sortBy) query.set('sortBy', params.sortBy);
@@ -76,6 +77,7 @@ export async function fetchMonitoring(params?: {
   if (params?.startDate) query.set('startDate', params.startDate);
   if (params?.endDate) query.set('endDate', params.endDate);
   if (params?.sourcePriority?.length) query.set('sourcePriority', params.sourcePriority.join(','));
+  if (params?.force) query.set('force', '1');
   const qs = query.toString();
   return fetchJson<MonitoringData>(`${BASE}/monitoring${qs ? `?${qs}` : ''}`);
 }
diff --git a/src/server/routes/mileage/manual-snapshot.test.ts b/src/server/routes/mileage/manual-snapshot.test.ts
new file mode 100644
index 0000000..37fb7f7
--- /dev/null
+++ b/src/server/routes/mileage/manual-snapshot.test.ts
@@ -0,0 +1,22 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import {
+  clearManualMonitoringSnapshot,
+  getManualMonitoringSnapshot,
+  storeManualMonitoringSnapshot,
+} from './manual-snapshot.js';
+
+const result = {
+  vehicles: [],
+  dailyTotals: [{ date: '2026-08-07', totalKm: 12 }],
+  start: '2026-08-07',
+  end: '2026-08-07',
+};
+
+test('reuses a manual snapshot only for its date range and TTL', () => {
+  clearManualMonitoringSnapshot();
+  storeManualMonitoringSnapshot(result, 1_000);
+  assert.ok(getManualMonitoringSnapshot('2026-08-07', '2026-08-07', 60_999));
+  assert.equal(getManualMonitoringSnapshot('2026-08-06', '2026-08-06', 60_999), null);
+  assert.equal(getManualMonitoringSnapshot('2026-08-07', '2026-08-07', 61_000), null);
+});
diff --git a/src/server/routes/mileage/manual-snapshot.ts b/src/server/routes/mileage/manual-snapshot.ts
new file mode 100644
index 0000000..f04d2f5
--- /dev/null
+++ b/src/server/routes/mileage/manual-snapshot.ts
@@ -0,0 +1,40 @@
+import type { RangeMileageResult } from './cache.js';
+
+const MANUAL_SNAPSHOT_TTL_MS = 60 * 1000;
+
+interface ManualSnapshot {
+  result: RangeMileageResult;
+  updatedAt: string;
+  expiresAt: number;
+}
+
+let snapshot: ManualSnapshot | null = null;
+
+export function storeManualMonitoringSnapshot(
+  result: RangeMileageResult,
+  now = Date.now(),
+): ManualSnapshot {
+  snapshot = {
+    result,
+    updatedAt: new Date(now).toISOString(),
+    expiresAt: now + MANUAL_SNAPSHOT_TTL_MS,
+  };
+  return snapshot;
+}
+
+export function getManualMonitoringSnapshot(
+  start: string,
+  end: string,
+  now = Date.now(),
+): ManualSnapshot | null {
+  if (!snapshot || snapshot.expiresAt <= now) {
+    snapshot = null;
+    return null;
+  }
+  if (snapshot.result.start !== start || snapshot.result.end !== end) return null;
+  return snapshot;
+}
+
+export function clearManualMonitoringSnapshot(): void {
+  snapshot = null;
+}
diff --git a/src/server/routes/mileage/monitoring-cache-policy.test.ts b/src/server/routes/mileage/monitoring-cache-policy.test.ts
new file mode 100644
index 0000000..629ee9f
--- /dev/null
+++ b/src/server/routes/mileage/monitoring-cache-policy.test.ts
@@ -0,0 +1,26 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import {
+  isMonitoringCacheEligible,
+  isMonitoringSnapshotScope,
+  shanghaiDate,
+} from './monitoring-cache-policy.js';
+
+test('uses the monitoring snapshot only for the current instrument day', () => {
+  const base = {
+    startDate: '2026-08-07',
+    endDate: '2026-08-07',
+    today: '2026-08-07',
+    sourcePriority: ['instrument'] as const,
+    force: false,
+  };
+  assert.equal(isMonitoringCacheEligible({ ...base, sourcePriority: [...base.sourcePriority] }), true);
+  assert.equal(isMonitoringCacheEligible({ ...base, startDate: '2026-08-06', sourcePriority: ['instrument'] }), false);
+  assert.equal(isMonitoringCacheEligible({ ...base, sourcePriority: ['gps'] }), false);
+  assert.equal(isMonitoringCacheEligible({ ...base, sourcePriority: ['instrument'], force: true }), false);
+  assert.equal(isMonitoringSnapshotScope({ ...base, sourcePriority: ['instrument'] }), true);
+});
+
+test('formats the current date in Asia/Shanghai', () => {
+  assert.equal(shanghaiDate(new Date('2026-08-06T16:30:00.000Z')), '2026-08-07');
+});
diff --git a/src/server/routes/mileage/monitoring-cache-policy.ts b/src/server/routes/mileage/monitoring-cache-policy.ts
new file mode 100644
index 0000000..6329fc9
--- /dev/null
+++ b/src/server/routes/mileage/monitoring-cache-policy.ts
@@ -0,0 +1,32 @@
+import type { MileageSourceGroup } from './source-policy.js';
+
+export function isMonitoringCacheEligible(input: {
+  startDate: string;
+  endDate: string;
+  today: string;
+  sourcePriority: MileageSourceGroup[];
+  force: boolean;
+}): boolean {
+  return !input.force && isMonitoringSnapshotScope(input);
+}
+
+export function isMonitoringSnapshotScope(input: {
+  startDate: string;
+  endDate: string;
+  today: string;
+  sourcePriority: MileageSourceGroup[];
+}): boolean {
+  return input.startDate === input.today
+    && input.endDate === input.today
+    && input.sourcePriority.length === 1
+    && input.sourcePriority[0] === 'instrument';
+}
+
+export function shanghaiDate(now = new Date()): string {
+  return new Intl.DateTimeFormat('en-CA', {
+    timeZone: 'Asia/Shanghai',
+    year: 'numeric',
+    month: '2-digit',
+    day: '2-digit',
+  }).format(now);
+}
diff --git a/src/server/routes/mileage/monitoring.ts b/src/server/routes/mileage/monitoring.ts
index 7165e7c..f01ddbe 100644
--- a/src/server/routes/mileage/monitoring.ts
+++ b/src/server/routes/mileage/monitoring.ts
@@ -8,6 +8,15 @@ import {
   parseMileageSourcePriority,
   protocolsForSourcePriority,
 } from './source-policy.js';
+import {
+  isMonitoringCacheEligible,
+  isMonitoringSnapshotScope,
+  shanghaiDate,
+} from './monitoring-cache-policy.js';
+import {
+  getManualMonitoringSnapshot,
+  storeManualMonitoringSnapshot,
+} from './manual-snapshot.js';
 
 const app = new Hono();
 
@@ -115,6 +124,7 @@ app.get('/', async (c) => {
   const range = normalizeRange(c.req.query('startDate') || '', c.req.query('endDate') || '');
   const sourcePriority = parseMileageSourcePriority(c.req.query('sourcePriority'));
   const protocolPriority = protocolsForSourcePriority(sourcePriority);
+  const force = c.req.query('force') === '1';
 
   const filterParams = {
     search: c.req.query('search') || '',
@@ -136,17 +146,66 @@ app.get('/', async (c) => {
   let filters: MonitoringFilters;
   let rangeDailyTotals: { date: string; totalKm: number }[] | undefined;
   let dateRange: { start: string; end: string } | undefined;
+  let dataUpdatedAt: string | undefined;
+  let cacheStatus: 'hit' | 'manual-hit' | 'refresh' | 'miss' | 'bypass' = 'bypass';
 
   if (range) {
-    try {
-      const result = await queryRangeMileage(range.start, range.end, protocolPriority);
-      allVehicles = result.vehicles;
-      rangeDailyTotals = result.dailyTotals;
-      dateRange = { start: result.start, end: result.end };
+    const cache = getCache();
+    const today = shanghaiDate();
+    const snapshotScope = isMonitoringSnapshotScope({
+      startDate: range.start,
+      endDate: range.end,
+      today,
+      sourcePriority,
+    });
+    const cacheEligible = isMonitoringCacheEligible({
+      startDate: range.start,
+      endDate: range.end,
+      today,
+      sourcePriority,
+      force,
+    });
+    const manualSnapshot = cacheEligible
+      ? getManualMonitoringSnapshot(range.start, range.end)
+      : null;
+    if (manualSnapshot) {
+      cacheStatus = 'manual-hit';
+      allVehicles = manualSnapshot.result.vehicles;
+      rangeDailyTotals = manualSnapshot.result.dailyTotals;
+      dateRange = { start: manualSnapshot.result.start, end: manualSnapshot.result.end };
+      dataUpdatedAt = manualSnapshot.updatedAt;
       filters = buildDateFilters(allVehicles);
-    } catch (e: unknown) {
-      console.error('monitoring range query error:', e);
-      return c.json(EMPTY_RESPONSE, 500);
+    } else if (cacheEligible && cache) {
+      cacheStatus = 'hit';
+      allVehicles = cache.vehicles.map(vehicle => ({
+        ...vehicle,
+        dailyMileage: { [range.start]: vehicle.dailyKm },
+        dailySourceProtocols: { [range.start]: vehicle.sourceProtocol },
+      }));
+      rangeDailyTotals = [{
+        date: range.start,
+        totalKm: Math.round(allVehicles.reduce((sum, vehicle) => sum + vehicle.dailyKm, 0)),
+      }];
+      dateRange = { ...range };
+      dataUpdatedAt = cache.updatedAt;
+      filters = cache.filters;
+    } else {
+      cacheStatus = cacheEligible ? 'miss' : 'bypass';
+      try {
+        const result = await queryRangeMileage(range.start, range.end, protocolPriority);
+        allVehicles = result.vehicles;
+        rangeDailyTotals = result.dailyTotals;
+        dateRange = { start: result.start, end: result.end };
+        filters = buildDateFilters(allVehicles);
+        if (force && snapshotScope) {
+          const stored = storeManualMonitoringSnapshot(result);
+          cacheStatus = 'refresh';
+          dataUpdatedAt = stored.updatedAt;
+        }
+      } catch (e: unknown) {
+        console.error('monitoring range query error:', e);
+        return c.json(EMPTY_RESPONSE, 500);
+      }
     }
   } else if (date) {
     try {
@@ -218,6 +277,7 @@ app.get('/', async (c) => {
   const paged = sorted.slice(offset, offset + limit);
   const total = filtered.length;
 
+  c.header('X-Mileage-Cache', cacheStatus);
   return c.json({
     vehicles: maskCustomerNames(paged),
     stats,
@@ -227,7 +287,7 @@ app.get('/', async (c) => {
     total,
     page,
     totalPages: Math.ceil(total / limit),
-    updatedAt: dateRange?.end || date || getCache()?.updatedAt || new Date().toISOString(),
+    updatedAt: dataUpdatedAt || dateRange?.end || date || getCache()?.updatedAt || new Date().toISOString(),
     sourcePriority,
   });
 });