According to the rolling curtain display method for comparing temporal GIS version data, the user selects two comparison times, the 
system performs device filtering according to the 
temporal information and the spatial index, and renders the image by the specified color, and returns the rendered geographic map, performs difference comparison according to the two times, calculates new equipment, modified equipment, deleted equipment, packs and returns the 
difference list. The method can view the change of the 
power equipment in the same position according to the linkage display of the mouse atthe same position, and obtain the difference between the two historical nodes of the 
power grid, which will play an important role in the operation management and planning prediction of the 
power grid, and improve the power, improve the functional location of power GIS in 
power grid equipment and the status and value of topological 
network data as a "
data source" in grid information systems. According to the rolling curtain display method for comparing temporal GIS version data, the management requirements tend to be refined, the development transition of the power grid is displayed accuratelyand visually, the demands of the planning construction of future power grid , 
engineering design and the like are auxiliary predicted, and certain decision support is provided for work of overhaul and technical changes, state maintenance and the like.