In some parameters, power system would appear the chaos phenomena, which is hazardous to its stable operation and lead to serious safety accident. Here, the chaotic features of the simple interconnected power system are analyzed through the maximum Lyapunov index figure, the time sequence diagram and phase diagram. Then we design the robust backstepping sliding method to control the chaos of power system which can quickly make the system reach the expected target. The efficiency of this method is further demonstrated by the simulation results, and the stability of power system will be in a good value.