The purpose of this study is to analyze the ride performance of a mining dump truck with hydro-pneumatic suspension system (HPSs). A mathematical model of hydro-pneumatic suspension strut with two oil chambers and one gas chamber is set up to determine its vertical force. And then a three-dimensional vehicle- road coupled dynamic model of a mining dump truck with 11 degrees of freedom under random road surface roughness is set up to analyze the effectiveness of HPSs in the direction of the ride comfort of vehicle. The time domain and power spectral density (PSD) of acceleration responses of the vertical driver’s seat, and the cab pitch and roll angles of a mining dump truck are chosen as objective functions to analyze the vehicle ride comfort performance of HPSs. Finally, the ride comfort performance of the HPSs under different operating conditions is analyzed respectively through objective functions. The obtained results indicate that the ride performance of a mining dump truck with HPSs are significantly improved under large amplitude excitation region of road surface roughness. Especially, the ride performance of a mining dump truck with HPSs has improved significantly at the low frequency region from 4 Hz to 10Hz in the vertical direction of driver’s seat and the cab pitch and roll angles under survey conditions.