否定一下我自己的回答，CellFormatting 不好，没有必要每次都刷。
你可以绑定完数据源再设置不同的ComboBox，代码如下：
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim data As DataTable = New DataTable
data.Columns.Add("Name")
data.Rows.Add(New Object() {"zhangsan"})
data.Rows.Add(New Object() {"lisi"})
data.Rows.Add(New Object() {"wangwu"})
data.Rows.Add(New Object() {"zhangsan"})
data.Rows.Add(New Object() {"lisi"})
data.Rows.Add(New Object() {"wangwu"})
data.Rows.Add(New Object() {"zhangsan"})
data.Rows.Add(New Object() {"lisi"})
data.Rows.Add(New Object() {"wangwu"})
Me.DataGridView1.DataSource = data
For i As Integer = 0 To data.Rows.Count - 1
Dim cell As DataGridViewComboBoxCell = TryCast(Me.DataGridView1(0, i), DataGridViewComboBoxCell)
cell.DisplayStyle = DataGridViewComboBoxDisplayStyle.DropDownButton
If i Mod 2 = 0 Then
Dim list As String() = {"1", "2", "3"}
cell.DataSource = list
Else
Dim list As String() = {"a", "b", "c"}
cell.DataSource = list
End If
Next
End Sub
