In order to study the vibration attenuation law of the hydro-pneumatic suspension system and obtain the vibration attenuation characteristics, the mathematical formula for damping force and the elastic force of the hydro-pneumatic suspension system were established considering the isothermal equilibrium process and the fast loading process, which was based on the structural characteristics of the hydro-pneumatic suspension system. The mathematical model of vibration of the hydropneumatic suspension system was derived based on the principle of conservation of energy. Through numerical simulation and experimental study, the vibration attenuation law of the oil and gas suspension system and the influence of relevant structural parameters on the attenuation law were obtained. The results show that the simulation results are basically consistent with the test results, and the attenuation amplitude of the vibration of the hydro-pneumatic suspension system shows a cyclical decreasing trend. Most of the vibration energy is consumed in the first two vibration cycles after excitation. Changes in the suspension structure parameters affect not only the amplitude attenuation but also the vibration attenuation period.