The utility model relates to a single cylinder type vibration damper, the vibration damper comprises a lower hinge, a guiding sleeve, a cylinder barrel, an upper end over, a piston rod assembly, a damping valve, a charge valve, and fins, the vibration damper is characterized in that an oil storage chamber is arranged in a cavity of the piston rod assembly, the fins in a certain number are machined and uniformly distributed on the external wall of the cylinder barrel, the upper end cover is connected with one end of the cylinder barrel, the other end of the cylinder barrel is connected and locked with the guiding sleeve via screw threads, a guiding belt, a dustproof loop, and a high pressure combination seal are arranged on the guiding sleeve, one end of the piston rod assembly and the lower hinge are connected and locked via screw threads, the lower hinge is provided with the charge valve, and one end of a piston of the piston rod assembly is provided with the damping valve. Since the oil storage chamber is arranged in the cavity of the piston rod assembly, the external wall of the cylinder barrel is made to be in contact with outside air, and purpose of good heat radiation effect is reached via enforcement of convection.