Abstract: In order to solve problems about the lack of combat scenes and echo simulation during the development of radar signal processor, it is proposed to use radar target simulation technology to simulate high confidence radar echo and complex electromagnetic environment. Based on analyzing the launching and flying flow of ballistic missile target, the system framework of radar target simulator is designed, and the combat scenes and radar echo,noise,clutter and jamming model are established. Then based on complex scene planning, real time radar echo is produced using graphics processing unit and the complex electromagnetic environment is generated. The radar target simulator can be used to solve the problem of testing radar interface, function and performance,provide more realistic and perfect test scenes, promote the radar system development and enhance the comprehensive testing capability of radar system. The simulator has shown a strong valuable engineering application.