On the basis of the analysis of basic working principle and structure of hydropneumatic suspension, the main parameters of its cylinder were calculated, and the mathematical model of the dual air chamber hydropneumatic suspension was created. A simulation model of the suspension was built by means of the AMESim software, the influence of the diameter of damping holes of cylinder、the initial pressure and initial volume of the accumulators on the output characteristic of hydropneumatic suspension was discussed. The results show the diameter of damping holes have a greater impact on the damping characteristics of hydropneumatic suspension, and the initial pressure and initial volume of the accumulators are essential for influencing the rigidy of suspension. The simulation results have a reference value on the design and selection of the parameters of the hydropneumatic suspension system.