Geographic Information System(GIS) is playing more and more important role in information management of power system. The popular GIS platform products include GeoMedia, Arc/Info, MapInfo and MicroStation. The choosing and using of power GIS platform should obey the rule in power system reality. Based on their preponderant application in geographic industry, Arc/Info and MapInfo have been successfully used in power system. The scheme of power GIS platform is put forward in this paper, referenced to the judgement and analysis of these prevailing platform, and the example of "GIS information system in Chongqing YuBei Power Supply Bureau" is given. This example shows the powerful twice developing ability, the profound network topology analysis ability of this method, which could also satisfy the needs of excessive and separate work nodes and parallel operation. All researches showed in this paper demonstrate the method could satisfy the need of power GIS.