diff --git a/frontend/src/pages/SocialInsurance.tsx b/frontend/src/pages/SocialInsurance.tsx
index 90971e0..ecd3875 100644
--- a/frontend/src/pages/SocialInsurance.tsx
+++ b/frontend/src/pages/SocialInsurance.tsx
@@ -1144,22 +1144,35 @@ function SpecialDeductionTab({ month, setMonth }: { month: string; setMonth: (m:
     } : { children: 0, elderly: 0, housing: 0, education: 0, infant: 0, remark: '' })
   }
 
-  /** 复制上月数据到编辑表单 */
-  const copyFromPrevMonth = (empId: string) => {
-    const prev = prevRecordMap.get(empId)
-    if (prev) {
-      setEditForm({
-        children: prev.children || 0,
-        elderly: prev.elderly || 0,
-        housing: prev.housing || 0,
-        education: prev.education || 0,
-        infant: prev.infant || 0,
-        remark: prev.remark || '',
-      })
-    } else {
-      toast.info(`${prevMonth} 无该员工的扣除记录`)
-    }
-  }
+  /** 批量复制上月数据到当月 */
+  const batchCopyMutation = useMutation({
+    mutationFn: async () => {
+      let copied = 0
+      for (const prev of prevRecords) {
+        await api.post('/social/special-deduction', {
+          employeeId: prev.employeeId,
+          month,
+          children: prev.children || 0,
+          elderly: prev.elderly || 0,
+          housing: prev.housing || 0,
+          education: prev.education || 0,
+          infant: prev.infant || 0,
+          remark: prev.remark || '',
+        })
+        copied++
+      }
+      return copied
+    },
+    onSuccess: (copied: number) => {
+      queryClient.invalidateQueries({ queryKey: ['special-deduction'] })
+      if (copied > 0) {
+        toast.success(`已复制 ${copied} 条 ${prevMonth} 的扣除数据到 ${month}`)
+      } else {
+        toast.info(`${prevMonth} 无可复制的扣除数据`)
+      }
+    },
+    onError: () => toast.error('复制上月数据失败'),
+  })
 
   const calcTotal = (f: any) => (f.children || 0) + (f.elderly || 0) + (f.housing || 0) + (f.education || 0) + (f.infant || 0)
 
@@ -1167,7 +1180,17 @@ function SpecialDeductionTab({ month, setMonth }: { month: string; setMonth: (m:
     <Card>
       <div className="flex items-center justify-between mb-3">
         <h2 className="text-sm font-medium">专项附加扣除 — {month}</h2>
-        <Input type="month" value={month} onChange={(e) => setMonth(e.target.value)} className="!w-32" />
+        <div className="flex items-center gap-2">
+          <Button
+            size="sm"
+            variant="secondary"
+            onClick={() => batchCopyMutation.mutate()}
+            disabled={batchCopyMutation.isPending || prevRecords.length === 0}
+          >
+            {batchCopyMutation.isPending ? '复制中...' : `复制上月(${prevMonth})`}
+          </Button>
+          <Input type="month" value={month} onChange={(e) => setMonth(e.target.value)} className="!w-32" />
+        </div>
       </div>
 
       {isLoading ? (
@@ -1209,7 +1232,6 @@ function SpecialDeductionTab({ month, setMonth }: { month: string; setMonth: (m:
                           <td className="py-1">
                             <div className="flex gap-1">
                               <Button size="sm" className="!h-7 !px-2" onClick={() => saveMutation.mutate({ employeeId: r.employeeId, ...editForm })} disabled={saveMutation.isPending}>保存</Button>
-                              <Button size="sm" variant="secondary" className="!h-7 !px-2" onClick={() => copyFromPrevMonth(r.employeeId)} disabled={!prevRecordMap.has(r.employeeId)}>复制上月</Button>
                               <Button size="sm" variant="secondary" className="!h-7 !px-2" onClick={() => { setEditing(null); setEditForm(null) }}>取消</Button>
                             </div>
                           </td>
@@ -1270,7 +1292,6 @@ function SpecialDeductionTab({ month, setMonth }: { month: string; setMonth: (m:
               </div>
               <div className="flex gap-2">
                 <Button size="sm" onClick={() => saveMutation.mutate({ employeeId: editing, ...editForm })} disabled={saveMutation.isPending}>保存</Button>
-                <Button size="sm" variant="secondary" onClick={() => copyFromPrevMonth(editing)} disabled={!prevRecordMap.has(editing)}>复制上月</Button>
                 <Button size="sm" variant="secondary" onClick={() => { setEditing(null); setEditForm(null) }}>取消</Button>
               </div>
             </div>