打开Exlce，
确定，然后
右击查看代码，把这段代码复制到新建的文件里面
此时Excel会给出提示，选择否，，系统会提示保存，在保存的时候选择启用宏的工作簿然后保存，此时Excel下拉框多选就搞定了，最后，代码如下：
Option Explicit Sub Worksheet_Change(ByVal Target As Range)
'让数据有效性选择 可以多选,重复选
Dim rngDV As Range
Dim oldVal As String
Dim newVal As String
If Target.Count > 1 Then GoTo exitHandler On Error Resume Next
Set rngDV = Cells.SpecialCells(xlCellTypeAllValidation)
On Error GoTo exitHandler If rngDV Is Nothing Then GoTo exitHandler If Intersect(Target, rngDV) Is Nothing Then
'do nothing
Else
Application.EnableEvents = False
newVal = Target.Value
Application.Undo
oldVal = Target.Value
Target.Value = newVal
If oldVal = "" Then
Else
If newVal = "" Then
Else
Target.Value = oldVal _
& ", " & newVal
End If
End If
End If exitHandler:
Application.EnableEvents = True
End Sub
优化后的代码
Option Explicit Sub Worksheet_Change(ByVal Target As Range)
'让数据有效性选择 可以多选,重复选
Dim rngDV As Range
Dim oldVal As String
Dim newVal As String
If Target.Count > 1 Then GoTo exitHandler On Error Resume Next
Set rngDV = Cells.SpecialCells(xlCellTypeAllValidation)
On Error GoTo exitHandler If rngDV Is Nothing Then GoTo exitHandler If Intersect(Target, rngDV) Is Nothing Then
'do nothing
Else
Application.EnableEvents = False
newVal = Target.Value
Application.Undo
oldVal = Target.Value
Target.Value = newVal
If oldVal = "" Then
Else
If newVal = "" Then
Else
If Target.Column <> 2 And Target.Column <> 3 And Target.Column <> 5 Then
Dim oldValArray
oldValArray = Split(oldVal, ",")
Dim exitVal As Boolean
exitVal = False
Dim i As Integer
Dim resultVal As String
For i = 0 To UBound(oldValArray)
If oldValArray(i) = newVal Then
exitVal = True
Else
If resultVal = "" Then
resultVal = oldValArray(i)
Else
resultVal = resultVal & "," & oldValArray(i)
End If
End If
Next
If exitVal = False Then
If oldVal = newVal Then
Target.Value = resultVal
Else
Target.Value = resultVal & "," & newVal
End If
Else
Target.Value = resultVal
End If
End If
End If
End If
End If exitHandler:
Application.EnableEvents = True
End Sub
转载自：https://www.cnblogs.com/boosasliulin/p/5970120.html