The slew control strategy of air defense phased array radars can affect the air defense missile system's operational effectiveness markedly. The effect on firing conditions of phased array radar by changing the pointing direction of phased array antenna in azimuth is analyzed, and an approach whether to put the slew control strategy into practice as well as a slew control method used in air defense target assignment is presented to achieve sufficient intercept performance. The method given in this paper is demonstrated by simulation application, the results show that the dynamic control of air defense phased array radar can significantly improve the operational effectiveness of the air defense system.