看错你的要求了，代码改成这样
Sub FileExis()
Dim MyFile As Object
Dim Str As String
Dim StrMsg As String
Str = ThisWorkbook.Path & "模版.xls"
Set MyFile = CreateObject("Scripting.FileSystemObject")
If MyFile.FileExists(Str) Then
Workbooks.Open ThisWorkbook.Path & "模版.xls"
Else
MsgBox "文件不存在!"
End If
Set MyFile = Nothing
End Sub
