Shock absorber

The invention discloses a shock absorber, and relates to the technical field of locomotive shock absorption. According to the key points of the technical scheme, the shock absorber comprises a pistonrod, a first hydraulic cylinder, a base and a second hydraulic cylinder, and further comprises a hydraulic buffer assembly fixed inside the base. The first hydraulic cylinder is filled with oil for buffering, and the hydraulic buffer assembly comprises a fixing seat, a connecting piece, a regulating valve, an upper valve body, a lower valve body and a piston assembly. Oil supply holes are formed in the side edge of the fixing seat, and the upper valve body is connected with a spring in a sleeved mode. An adjusting block is provided with an oil outlet hole and a through hole. The inside of thelower valve body is hollow and communicates with an oil pipe, and the inside of the upper valve body is hollow as well. The opening diameter of the lower valve body is smaller than the radius of the upper valve body at the abu