方法一、

看字符的ASC
小于0的为中文

Private Sub Command1_Click()
MsgBox CT(Text1.Text) 'True：有中文；False：无中文
End Sub

Private Function CT(Text As String) As Boolean
Dim l As Long
Dim i As Long
l = Len(Text)
CT = False

For i = 1 To l
If Asc(Mid(Text, i, 1)) < 0 Then
CT = True
Exit Function
End If
Next

End Function

方法二、

Private Declare Function lstrlen Lib "kernel32" Alias "lstrlenA" (ByVal lpString As String) As Long


Private Sub Command1_Click()
Dim strSrc As String

strSrc = "abc中文"
If lstrlen(strSrc) - Len(strSrc) > 0 Then
Debug.Print "strSrc中包含双字节字符"
Else
Debug.Print "strSrc中不包含双字节字符"
End If

strSrc = "abcdef"
If lstrlen(strSrc) - Len(strSrc) > 0 Then
Debug.Print "strSrc中包含双字节字符"
Else
Debug.Print "strSrc中不包含双字节字符"
End If
End Sub  

方法三、

Strlen() 中文化字串长度，相对Len()
StrLeft() 中文化取左字串，相对Left()
StrRight() 中文化取右字串，相对Right()
isChinese() Check某个字是否中文字

Public Function SubStr(ByVal tstr As String, start As Integer, Optional leng As Variant) As String
Dim tmpstr As String
If IsMissing(leng) Then
tmpstr = StrConv(MidB(StrConv(tstr, vbFromUnicode), start), vbUnicode)
Else
tmpstr = StrConv(MidB(StrConv(tstr, vbFromUnicode), start, leng), vbUnicode)
End If
SubStr = tmpstr
End Function

Public Function Strlen(ByVal tstr As String) As Integer
Strlen = LenB(StrConv(tstr, vbFromUnicode))
End Function

Public Function StrLeft(ByVal str5 As String, ByVal len5 As Long) As String
Dim tmpstr As String
tmpstr = StrConv(str5, vbFromUnicode)
tmpstr = LeftB(tmpstr, len5)
StrLeft = StrConv(tmpstr, vbUnicode)
End Function

Public Function StrRight(ByVal str5 As String, ByVal len5 As Long) As String
Dim tmpstr As String
tmpstr = StrConv(str5, vbFromUnicode)
tmpstr = RightB(tmpstr, len5)
StrLeft = StrConv(tmpstr, vbUnicode)
End Function

Public Function isChinese(ByVal asciiv As Integer) As Boolean
If Len(Hex$(asciiv)) > 2 Then
isChinese = True
Else
isChinese = False
End If
End Function

方法四、

Dim m_Str1 As String,m_Str2 As String
m_Str1 ="hjlkj卓越。"

m_Str2= StrConv(m_Str1, vbFromUnicode )
if lenB(m_Str1)<>lenB(m_Str2) then
'字符串中存在中文字符。
end if