The application provides a shock absorber which comprises an oil storage cylinder, a working cylinder, a guide seat, a piston rod, a seal ring, a piston and an auxiliary piston. The lower part of theworking cylinder is connected onto the bottom of the oil storage cylinder by means of a bottom valve. The upper part of the working cylinder is connected with the upper part of the oil storage cylinder by means of the guide seat. The lower end of the piston rod extends into the working cylinder. The upper end of the piston rod extends toward the exterior of the upper part of the oil storage cylinder. The seal ring is mounted at the connection part of the guide seat and the oil storage cylinder, and sleeves the piston rod. The piston is fixed at the lower part of the piston rod and is arrangedin the working cylinder. The auxiliary piston is connected to the lower part of the piston rod, is positioned below the piston, and comprises a taper reduction sleeve, a belleville spring, a gland anda chuck body. Through the adoption of the structure, the shock absorber is better in shock absorbing effect and longer in service life.