Abstract The frame structure of and GIS application in weather modification terminal software are summarized in aspects of features and problems.A plug-in weather modification system based on open source GIS is designed according to the specific business needs of weather modification.The system structure is developed on .NET and designed by the secondary development of plug-in GIS application framework.The GIS function is realized through a combination of GDAL and SharpMap,thereafter the function of plug-in modules and the realization of GIS modules are described in detail,and the specific design method for weather modification command system is also given.Actual operating practices show that,the command system improves the efficiency of function expansion and post-maintenance of weather modification business system.