Aiming at the request of EPS system for the robust stability and the dynamic characteristic, the dynamics model of an electric power steering system (EPS) is established , the outer ring mixed H2/H∞ control based on genetic algorithm decides the values of the target torque and solves the perturbation problem, the inner ring control with PID control algorithm will never compromise with current real-time control. Simulation results show that the application of mixed H2/H∞ in the outer ring for current decision can make the EPS system stable and realize the ideal control performance, can also obtain the low frequency information from the surface of the road and depress the high frequency interference.With the application of current tracking loop PID control, EPS system has good dynamic characteristics of the target current real-time tracking, so that electric power steering system has better stability and traking performence.