diff --git a/docs/bi-refactor-roadmap.md b/docs/bi-refactor-roadmap.md
index 253b799..d6e8477 100644
--- a/docs/bi-refactor-roadmap.md
+++ b/docs/bi-refactor-roadmap.md
@@ -171,6 +171,7 @@ SUM(fee) / NULLIF(SUM(kwh), 0)
 
 - 里程年度归因使用考核台账 `current_mileage` 快照，按车辆目标封顶后加总完成量与缺口，并自动核对归因合计和目标汇总；带日期的 OneOS 里程只用于车辆实时明细。
 - 里程考核目标接口发布车辆台账 `MAX(update_time)`，统计页使用真实日期和时间展示数据截至点，不再用页面访问日或考核结束日代替快照时间。
+- 里程考核接口区分目标声明台数与当前有效车辆数；两者不一致时页面明确标注缺少或超配数量，并说明完成率、缺口和归因的实际计算范围。
 - 已完成电能数据截至时间和实际趋势月展示。
 - 电能日期下钻自动核对日汇总与订单全量合计的日期、车辆范围、电量和费用，并显式展示通过或差异状态。
 - 已完成氢能结构化故障状态与重试体验。
diff --git a/src/modules/mileage/StatisticsView.tsx b/src/modules/mileage/StatisticsView.tsx
index 06f3129..80640e3 100644
--- a/src/modules/mileage/StatisticsView.tsx
+++ b/src/modules/mileage/StatisticsView.tsx
@@ -6,7 +6,7 @@ import {
   Cell, LabelList,
 } from 'recharts';
 import {
-  Truck, ChevronDown, Maximize2, Minimize2,
+  AlertTriangle, Truck, ChevronDown, Maximize2, Minimize2,
   Search, ArrowUpDown, X, RotateCcw, Calendar,
 } from 'lucide-react';
 import type { TargetSummary, TargetVehicle, TargetYearlyAssessment, TrendPoint } from './types';
@@ -14,6 +14,7 @@ import { fetchTargets, fetchTargetVehicles, fetchTrend } from './api';
 import Blur from '../../components/Blur';
 import { weightedCompletionRate } from '../../shared/analytics/metrics';
 import { formatMileageSnapshotDateTime } from './data-freshness';
+import { assessVehicleCoverage } from './assessment-coverage';
 import MileageAttributionView from './MileageAttributionView';
 import {
   filterAttributionVehicles,
@@ -94,6 +95,9 @@ export default function StatisticsView() {
   const selectedTarget = targets.find(t => t.id === selectedTargetId);
   const selectedTargetVehicles = selectedTargetId === null ? [] : targetVehiclesMap[selectedTargetId] || [];
   const selectedAssessment = selectedTarget ? getTargetAssessment(selectedTarget, assessmentYearMap[selectedTarget.id]) : null;
+  const selectedCoverage = selectedTarget
+    ? assessVehicleCoverage(selectedTarget.declaredVehicleCount, selectedTarget.vehicleCount)
+    : null;
   const selectedAssessmentYear = selectedAssessment?.yearNumber;
   const selectedCompletion = selectedAssessment?.completionRate ?? selectedTarget?.avgCompletion ?? 0;
   const selectedRemaining = selectedAssessment?.remaining ?? 0;
@@ -361,6 +365,20 @@ export default function StatisticsView() {
         </motion.div>
       )}
 
+      {selectedTarget && selectedCoverage && selectedCoverage.status !== 'matched' && (
+        <div role="alert" className="flex items-start gap-2 rounded-xl border border-amber-200 bg-amber-50 px-3 py-2 text-amber-900">
+          <AlertTriangle size={15} className="mt-0.5 shrink-0 text-amber-600" />
+          <div className="min-w-0 text-[11px] font-bold leading-5">
+            <span className="font-black">考核车辆配置不一致：</span>
+            目标 {selectedCoverage.declaredCount} 台，当前有效 {selectedCoverage.activeCount} 台，
+            {selectedCoverage.status === 'missing'
+              ? `缺少 ${Math.abs(selectedCoverage.difference)} 台`
+              : `超出 ${selectedCoverage.difference} 台`}。
+            完成率、缺口和归因按当前有效车辆计算。
+          </div>
+        </div>
+      )}
+
       {selectedTarget && (
         <MileageAttributionView
           vehicles={selectedTargetVehicles}
diff --git a/src/modules/mileage/assessment-coverage.test.ts b/src/modules/mileage/assessment-coverage.test.ts
new file mode 100644
index 0000000..b423d3d
--- /dev/null
+++ b/src/modules/mileage/assessment-coverage.test.ts
@@ -0,0 +1,25 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { assessVehicleCoverage } from './assessment-coverage.js';
+
+test('reports matched, missing, and excess assessment vehicles', () => {
+  assert.deepEqual(assessVehicleCoverage(50, 46), {
+    status: 'missing',
+    declaredCount: 50,
+    activeCount: 46,
+    difference: -4,
+    coverageRate: 92,
+  });
+  assert.equal(assessVehicleCoverage(40, 40).status, 'matched');
+  assert.equal(assessVehicleCoverage(40, 42).status, 'excess');
+});
+
+test('normalizes invalid counts without inventing configured vehicles', () => {
+  assert.deepEqual(assessVehicleCoverage(Number.NaN, -2), {
+    status: 'matched',
+    declaredCount: 0,
+    activeCount: 0,
+    difference: 0,
+    coverageRate: 100,
+  });
+});
diff --git a/src/modules/mileage/assessment-coverage.ts b/src/modules/mileage/assessment-coverage.ts
new file mode 100644
index 0000000..f85c334
--- /dev/null
+++ b/src/modules/mileage/assessment-coverage.ts
@@ -0,0 +1,26 @@
+export type AssessmentCoverageStatus = 'matched' | 'missing' | 'excess';
+
+export interface AssessmentCoverage {
+  status: AssessmentCoverageStatus;
+  declaredCount: number;
+  activeCount: number;
+  difference: number;
+  coverageRate: number;
+}
+
+function count(value: number): number {
+  return Math.max(0, Math.trunc(Number(value) || 0));
+}
+
+export function assessVehicleCoverage(declaredCount: number, activeCount: number): AssessmentCoverage {
+  const declared = count(declaredCount);
+  const active = count(activeCount);
+  const difference = active - declared;
+  return {
+    status: difference === 0 ? 'matched' : difference < 0 ? 'missing' : 'excess',
+    declaredCount: declared,
+    activeCount: active,
+    difference,
+    coverageRate: declared > 0 ? active / declared * 100 : active === 0 ? 100 : 0,
+  };
+}
diff --git a/src/modules/mileage/types.ts b/src/modules/mileage/types.ts
index f629677..123c4b7 100644
--- a/src/modules/mileage/types.ts
+++ b/src/modules/mileage/types.ts
@@ -65,6 +65,7 @@ export interface TargetSummary {
   id: number;
   targetName: string;
   snapshotUpdatedAt: string | null;
+  declaredVehicleCount: number;
   vehicleCount: number;
   totalMileagePerVehicle: number;
   annualMileagePerVehicle: number;
diff --git a/src/server/routes/mileage/targets.ts b/src/server/routes/mileage/targets.ts
index 0e80115..1863d81 100644
--- a/src/server/routes/mileage/targets.ts
+++ b/src/server/routes/mileage/targets.ts
@@ -201,7 +201,8 @@ app.get('/', async (c) => {
         id: t.id,
         targetName: t.target_name,
         snapshotUpdatedAt: s.snapshot_updated_at || null,
-        vehicleCount: Number(s.total) || t.vehicle_count,
+        declaredVehicleCount: Number(t.vehicle_count) || 0,
+        vehicleCount: s.total == null ? 0 : Number(s.total) || 0,
         totalMileagePerVehicle: Number(t.total_mileage_per_vehicle),
         annualMileagePerVehicle: Number(t.annual_mileage_per_vehicle),
         assessmentYears: t.assessment_years,