Power steering system is one of the key parts of distributed electric drive vehicles in their design and assembly. Power steering system is not only a complex nonlinear dynamic system with uncertainty, unmodeled dynamics, measurement noise and interference, but a hybrid system including both discrete event and continuous dynamics also. The structure, control function and dynamic behavior of power steering system were analyzed. The functional model structure and implement model structure reflecting both the discrete and continuous dynamic behavior of hybrid system of power steering system were established. The switched control of hybrid system was established. The pylon course slalom test was executed under 20 km/h and 40 km/h speed condition respectively. The results show that the peak value and standard deviation of steering torque are reduced by 4093% and 4099% respectively when 20 km/h speed, and by 31.11% and 32.12% respectively when 40 km/h speed, the steering portability is improved obviously. The dynamic mechanism and equation has improved the robustness of power steering system. It has practical significance to the overall design of power steering system, the improvement and optimization of system’s function and the steering manipulation safety.