Hydraulic shock absorbers are widely used in automobiles suspension system. The principle is that when the frame and the axle do reciprocating relative motion and the piston reciprocates in the shock absorber cylinder, the oil in the shock absorber shell will repeatedly flow into another cavity from the cavity through some narrow pores. At this point, the friction between the liquid and the inner wall and the internal friction of the liquid molecules will form a damping force on the vibration. This paper is organized by henan guanbo shock absorber co., LTD