Damping system of commercial vehicle

The invention provides a damping system of a commercial vehicle. The damping system comprises a single chip microcomputer, an alertor, a pressure sensor, two displacement sensors and a hydraulic shock absorber. The hydraulic shock absorber is a hydraulic shock absorber with the length of a piston rod being variable and comprises the piston rod and a first cavity. A second cavity is formed in the first cavity. A motor is arranged at the top of the first cavity. A gear is arranged at an output shaft of the motor. The outside of the gear is engaged with a rack. The lower end of the rack is connected with the upper end of the piston rod. The lower end of the piston rod is inserted into the second cavity in a penetrating mode. A second connecting ring is arranged at the lower end of the second cavity. A first connecting ring is arranged the upper end of the first cavity. The two displacement sensors are arranged on the first connecting ring and the connecting position of the first cavity and the second cavity corr