In development of system software for UAV Ground Control Station (GCS),it is essential to realize parallel development effectively and deal with the constantly changing demand.The working principles and realization ways of plug-in framework are presented,and the design scheme of plug-in UAV mission planning software framework is given.The design idea of the application framework is described in detail,and some key technologies of the plug-in manager,user interface management and the internal message communication mechanism are discussed.The design scheme was applied to an actual project and realized all-plug-in mission planning software framework,which proved that the framework can significantly improve the efficiency of software development,and improve the quality of software product.