In order to study the influence of hydro-pneumatic suspension on vehicle ride comfort, a vehicle dynamics model was established for a 90 t wide body vehicle, and the AMESim simulation model of front suspension 1/4 vehicle hydro-pneumatic suspension was built; the mechanism of vehicle ride comfort under random road input was studied. Based on the passive suspension model, the active control system was added to make a comparative analysis with the passive suspension, and the active suspension was optimized by using AMESim/design exploration function.The results show that the vehicle smoothness is good when the vehicle speed is not more than 40 km/h and the initial gas chamber pressure is 7.7 MPa; active suspension can attenuate vibration better than passive suspension, which greatly improves the ride comfort of the vehicle; on the basis of ensuring the constant constraint conditions, the optimized weighted RMS acceleration is reduced by 18.72%, which effectively improves the ride comfort and ride comfort of harvers. The research results provide reference for the design and optimization of hydro-pneumatic suspension.