The single-cylinder inflatable two-way shock absorber consists of a cylinder, shock-absorbing oil, nitrogen, piston rod and sealing cover. Its main features are: a compression nut, an expansion valve spring, an expansion valve plate, and a piston. , piston rod, compression valve plate and compression valve spring form a piston assembly. As the piston moves, the piston assembly is loaded into the cylinder. Nitrogen is filled between the oil and the top of the cylinder. When the vehicle body vibrates, the oil repeatedly moves up and down in the cylinder. The cavity flows through the narrow pores on the piston, converting the body vibration energy into heat energy and dissipating it. The invention can effectively attenuate the body vibration of automobiles, motorcycles and other motor vehicles.