The shock absorber is a component to improve the driving comfort of the car and attenuate the vibration of the frame and body. When the vehicle is running, the shock absorber spring is mainly used to absorb the bumps and vibrations caused by uneven road surfaces. As an elastic element, the spring can also produce reciprocating bounce motion while absorbing and filtering the bumpy vibration of the road surface. The main function of the shock absorber is to suppress the repeated bouncing of the shock absorbing spring after absorbing various impacts from the road surface, so as to accelerate the attenuation of the natural vibration of the spring and provide better driving comfort for the vehicle.