In the course of air defense and anti-missile battles, ground-based radars mission shifting for ballistic targets detection is very important. In this paper, a simulation and evaluation based radars mission shifting design method and model system are provided, which synthesize the thoughts of prediction and multi-attribute evaluation, by combining experts’ experience with analytical calculation and qualitative analysis with quantitative analysis. Then radars mission shifting schemes contrast and optimization is realized through shifting schemes designing, shifting process simulation, shifting performance evaluation and so on. Thus, the method proposed in this paper can ensure the objectivity and effectivity of shifting process simulation and shifting performance evaluation using shifting performance criterion, and optimize the shifting schemes continuously, which could offer beneficial references to radars shifting modelling and schemes design for air defense and anti-missile.