Abstract: Power supply system is a fundamental subsystem of radar with the role to provide power for other subsystems. With the increasement of radar power as well as more and more weaponries working together with radar, power supply system is becoming more and more advanced and complicated. On the other hand, compatibility and stability of power supply system need to be studied in depth. In order to design a power supply system run stably and reliably in radar with high performance as well as low cost, the idea named power supply system technology is stated and the current development status of the technology is briefly described, the trends of power supply system technology used in radar are discussed. In the end, the developing route of power supply system in radar is summarized.