Surveillance radar antijamming closed-loop simulation is of great significance for researches on radar system antijamming performance improvement and new kinds of jamming patterns. Total system signal grade simulation model, which can simulate jamming patterns like dense false target jamming, frequency spot jamming, sweep frequency jamming, and antijamming measures such as sidelobe blocking, sidelobe cancellation etc., is designed by analyzing the simulation process of radar jamming and antijamming signals, building physical models of radar system, typical jamming patterns and antijamming measures. The function of simulation model is proved effective by comparing with the results of real equipment tests.