Power steering pump is the power source of hydraulic power steering system, it is through the engine as a transmission medium, the mechanical energy is converted to hydraulic energy, the steering gear through the pump output of hydraulic oil to convert hydraulic energy into mechanical energy, thus playing a role in reducing the intensity of the driver's operation, improve the maneuverability of the vehicle; through the pressure safety valve to control the internal pressure of power steering pipeline to ensure that the steering system is safe; through the flow control valve to control the steering system flow, to ensure that the driver steers the feel of the vehicle when it is running at high speeds.