diff --git a/frontend/mock/dashboard.ts b/frontend/mock/dashboard.ts
index b0c9532..3fec756 100644
--- a/frontend/mock/dashboard.ts
+++ b/frontend/mock/dashboard.ts
@@ -4,6 +4,11 @@ import type { MockMethod, MockRequest } from './types'
 function getToday(): string { return new Date().toISOString().slice(0, 10) }
 function daysAgo(n: number): string { const d = new Date(); d.setDate(d.getDate() - n); return d.toISOString().slice(0, 10) }
 
+// 计算日期范围天数
+function getDays(startDate: string, endDate: string): number {
+  return Math.max(1, Math.round((new Date(endDate).getTime() - new Date(startDate).getTime()) / 86400000) + 1)
+}
+
 // 不同日期范围的数据倍率（模拟不同日期的数据差异）
 function getMultiplier(startDate: string, endDate: string): number {
   const today = getToday()
@@ -78,10 +83,11 @@ const mock: MockMethod[] = [
     method: 'get',
     response: (req: MockRequest) => {
       const m = getMultiplier(req.query.startDate, req.query.endDate)
+      const days = getDays(req.query.startDate, req.query.endDate)
       return {
         code: 0,
         data: {
-          items: baseMachineRank.map(r => ({ ...r, quantity: Math.round(r.quantity * m) })),
+          items: baseMachineRank.map(r => ({ ...r, quantity: Math.round(r.quantity * m * days) })),
         },
       }
     },
@@ -91,10 +97,11 @@ const mock: MockMethod[] = [
     method: 'get',
     response: (req: MockRequest) => {
       const m = getMultiplier(req.query.startDate, req.query.endDate)
+      const days = getDays(req.query.startDate, req.query.endDate)
       return {
         code: 0,
         data: {
-          items: baseWorkerRank.map(r => ({ ...r, totalQuantity: Math.round(r.totalQuantity * m) })),
+          items: baseWorkerRank.map(r => ({ ...r, totalQuantity: Math.round(r.totalQuantity * m * days) })),
         },
       }
     },
@@ -124,14 +131,15 @@ const mock: MockMethod[] = [
     method: 'get',
     response: (req: MockRequest) => {
       const m = getMultiplier(req.query.startDate, req.query.endDate)
+      const days = getDays(req.query.startDate, req.query.endDate)
       return {
         code: 0,
         data: {
-          items: baseWorkshopProduction.map(w => ({
-            ...w,
-            quantity: Math.round(w.quantity * m),
-            avgQuantity: Math.round(w.avgQuantity * m * 10) / 10,
-          })),
+          items: baseWorkshopProduction.map(w => {
+            const totalQty = Math.round(w.quantity * m * days)  // 多天总量 = 单天 × 天数
+            const avgQty = Math.round(totalQty / days / w.machineCount * 10) / 10  // 日均单机产量
+            return { ...w, quantity: totalQty, avgQuantity: avgQty }
+          }),
         },
       }
     },
diff --git a/frontend/src/views/dashboard/DashboardPage.vue b/frontend/src/views/dashboard/DashboardPage.vue
index 0fea062..6d14633 100644
--- a/frontend/src/views/dashboard/DashboardPage.vue
+++ b/frontend/src/views/dashboard/DashboardPage.vue
@@ -136,7 +136,16 @@
         <el-card shadow="hover">
           <template #header>
             <div class="card-header">
-              <span class="card-title">车间平均单机产量（{{ workshopDateLabel }}）<el-tooltip content="各车间总产量除以机床数量，反映每台机床的平均产出效率，消除车间规模差异。" placement="top"><span class="info-icon">ⓘ</span></el-tooltip></span>
+              <span class="card-title">车间平均单机产量（{{ workshopDateLabel }}）<el-tooltip placement="top">
+                <template #content>
+                  <div style="max-width: 360px; line-height: 1.6">
+                    <b>统计规则：</b>车间总产量 ÷ 车间机床数 ÷ 天数<br/><br/>
+                    <b>数据来源：</b>系统每日凌晨1:00自动执行日终汇总，将每台机床当天所有产量分段按程序名合并计算，生成日产量记录。多天范围取日均单机产量。<br/><br/>
+                    <b>产量计算：</b>以NC程序名标识零件，程序切换时自动结算上一段产量。同程序多次出现时分段记录、日汇总合并。含手工修正值。
+                  </div>
+                </template>
+                <span class="info-icon">ⓘ</span>
+              </el-tooltip></span>
               <div class="date-filter">
                 <el-radio-group v-model="workshopDateType" size="small" @change="onWorkshopDateChange">
                   <el-radio-button value="today">今日</el-radio-button>
@@ -291,6 +300,14 @@ const workshopDateLabel = computed(() => dateLabels[workshopDateType.value])
 const machineDateLabel = computed(() => dateLabels[machineDateType.value])
 const workerDateLabel = computed(() => dateLabels[workerDateType.value])
 
+// 车间平均单机产量的日均单位
+const workshopDays = computed(() => {
+  const { startDate, endDate } = getDateRange(workshopDateType.value, workshopDateRange.value)
+  return Math.max(1, Math.round((new Date(endDate).getTime() - new Date(startDate).getTime()) / 86400000) + 1)
+})
+const workshopUnit = computed(() => workshopDays.value > 1 ? '件/台/天' : '件/台')
+const workshopUnitLabel = computed(() => workshopDays.value > 1 ? '日均' : '平均')
+
 function getDateRange(type: DateType, customRange?: [string, string]): { startDate: string; endDate: string } {
   const today = new Date()
   const fmt = (d: Date) => d.toISOString().slice(0, 10)
@@ -355,22 +372,24 @@ function alertTypeLabel(type: string): string {
 
 function initWorkshopChart() {
   if (workshopChartRef.value && workshopData.value.length) {
+    const unit = workshopUnit.value
+    const unitLabel = workshopUnitLabel.value
     workshopChart = echarts.init(workshopChartRef.value)
     workshopChart.setOption({
       tooltip: {
         trigger: 'axis',
         formatter: (params: any) => {
           const d = workshopData.value[params[0].dataIndex]
-          return `${d.workshopName}<br/>平均产量: ${params[0].value} 件/台<br/>总产量: ${d.quantity} 件<br/>机床数: ${d.machineCount} 台`
+          return `${d.workshopName}<br/>${unitLabel}产量: ${params[0].value} ${unit}<br/>总产量: ${d.quantity} 件<br/>机床数: ${d.machineCount} 台`
         },
       },
-      grid: { left: 50, right: 20, top: 20, bottom: 30 },
+      grid: { left: 60, right: 20, top: 20, bottom: 30 },
       xAxis: { type: 'category', data: workshopData.value.map(i => i.workshopName), axisLabel: { fontSize: 12 } },
-      yAxis: { type: 'value', name: '件/台', axisLabel: { fontSize: 12 } },
+      yAxis: { type: 'value', name: unit, axisLabel: { fontSize: 12 } },
       series: [{
         type: 'bar', data: workshopData.value.map(i => i.avgQuantity),
         itemStyle: { color: '#67C23A', borderRadius: [4, 4, 0, 0] }, barWidth: '40%',
-        label: { show: true, position: 'top', formatter: '{c} 件/台', fontSize: 12 },
+        label: { show: true, position: 'top', formatter: `{c} ${unit}`, fontSize: 12 },
       }],
     })
   }