A conversion type motor vehicle damping device comprises a converter, a damping cylinder and a hydraulic pipeline. The damping cylinder and the converter are filled with hydraulic oil and are connected through a hydraulic pipeline. The converter is formed by coaxially installing a driving cylinder and a pressure cylinder, a
piston and a
piston rod are installed in the converter, by means of the conversion effect of force, small elastic pressure is applied to the
piston of the converter, the
piston rod can be pushed to extrude hydraulic oil, large pressure intensity is generated and acts on the damping cylinder, and the
piston rod generates large stretching supporting force. The damping cylinder is connected with a wheel support of the motor vehicle, can drive a piston in the damping cylinder to transmit hydraulic oil to the converter along with
jumping of wheels, and counteracts the piston of the converter to enable the piston to move so as to absorb upward
impact on the wheels. The damping cylinder is controlled by applying a force conversion principle, so that the damping device has the advantages of convenience in adjustment, stability, reliability and no need of high-pressure
nitrogen and air bag sealing.