After introducing the current development of the excitation control method in power system, a novel control strategy ---impulsive control is proposed and a set of stability criteria for uncertain impulsive dynamical system and its principle are expounded. Then shows the mathematical model in excitation system and uses impulsive control in this system. Finally, it uses the AVR+PSS and impulsive control in excitation system respectively and observes the curve difference in Matlab when power system is changed into small disorder. The results indicate that using impulsive control can achieve faster convergence speed and faster response and improve the performance of the system remarkably.