Dim lsjl As DataRow = DataTables("POS机绑定商户历史记录表").Find("机具条码='" & sr("机具条码") & "' and 解绑日期 is null")
改成
Dim lsjl As DataRow = DataTables("POS机绑定商户历史记录表").Find("机具条码='" & sr("机具条码") & "'")