In order to improve the ride comfort of the bus and the roll stiffness of the bus body when turning, a coaxial interconnected hydro-pneumatic suspension model was established. In this paper, the structure and working principle of the single cylinder type hydro-pneumatic spring and the coaxial connected hydro-pneumatic suspension are introduced, and on this basis, the mathematical model is established. By comparing the simulation analysis, it shows the superiority of the ride comfort and anti-roll with the air spring.