The character of SIMULINK and principle of certam radar antenna followmg system are mtroduced here. The method to build model facing block diagram by usmg SIMULINK and the process of digital simulation are discussed emphatically. The dynamlc performance of certam radar antenna (the branch of azimuth) following system is also analyzed here. All of these make an mstructive role in analysis of performance of the complicate control system by using SIMULINK.