The mechanical steering system is composed of steering wheel, steering shaft, universal joint, steering gear, steering rocker arm, steering tie rod, tie rod, knuckle arm, knuckle and trapezoidal arm. Mechanical steering system refers to a series of devices used to change or maintain the driving or reverse direction of the vehicle. The working principle of the mechanical steering system is: when the vehicle turns, the driver rotates the steering wheel according to the needs, and transmits the rotation action to the universal joint and steering gear through the steering shaft. The steering gear is responsible for converting the rotation action into the swing of the steering rocker arm, driving the action of the steering tie rod, steering knuckle arm and steering knuckle. Since the steering knuckle and steering knuckle arm are fixed on the frame through the steering shaft, the steering knuckle rotates relative to the frame, The wheels fixed on the steering knuckle produce steering offset to complete the steering action.