1、合并的时候，不要触发datacolchanged、DataRowAdded事件；

 2、不要在代码中使用find函数查找数据；

 3、你要确定，是合并的过程慢，还是说保存的过程慢。

请发送实例测试。

If DataTables.Contains("dtkb") = False  Then
    Dim dtb As New DataTableBuilder("dtkb")
    dtb.AddDef("_Identify", Gettype(Integer))
    dtb.AddDef("_SortKey", Gettype(Integer))
    dtb.AddDef("_Locked", Gettype(Boolean))
    For n As Integer = 0 To 100
        dtb.AddDef("F" & n,Gettype(String), 100)
    Next
    dtb.Build()
End If
DataTables("dtkb").DataRows.Clear
Dim dlg As new OpenFileDialog
dlg.Filter = "文本文件|*.txt"

If dlg.ShowDialog = DialogResult.OK Then
   
    Dim st As Date = Date.Now
    \'要测试耗时的代码
   
   
    Dim strs As String = FileSys.ReadAllText(dlg.FileName)
    strs = strs.Replace(vblf,"")
    Dim rs() As String = strs.Split(vbcr)
    DataTables("dtkb").StopRedraw
    For i As Integer = 0 To rs.Length - 1
        \'Dim cs() As String = rs(i).Split(vbtab)
        Dim cs() As String = rs(i).Split(",")
        Dim dr As DataRow = DataTables("dtkb").Addnew()
        For n As Integer = 0 To cs.Length - 1
            dr("F" & n) = cs(n)
        Next
    Next
   
    DataTables("dtkb").ResumeRedraw
    MessageBox.Show("耗时: " & (Date.Now - st).TotalSeconds & "秒")
End If