For simple structure and good nonlinear variable stiffness and damping characteristics, hydropneumatic suspension is widely used. According to the structure characteristics of the single chamber hydropneumatic suspension, it was parameter treated, and the experimental design analysis was performed using a quarter vehicle vibration system model. The structure parameters having largest influence on vehicle vibration performance and their combination were determined. Structural parameter optimization analysis was carried out to analyze the distribution of the structural parameters when the vehicle vibration performance was optimal. The parameters were optimized based on orthogonal experiment. And combining with the hydro pneumatic suspension mathematical model, ratio of piston diameter to piston rod diameter,ratio of damping hole diameter to piston rod diameter, ratio of oneway valve equivalent diameter to damping hole diameter were used to simplify the design process. The effects of hydropneumatic suspension parameters on vehicle running smooth and safe operation were analyzed,as well as the influence sequence measured by influence degree,then the main factors and secondary factors were determined. Through optimization analysis to the parameters of hydropneumatic suspension,it is known that: the initial position of the suspension affects the performance of the hydropneumatic suspension, followed by the ratio of piston diameter to piston rod diameter; design variables influencing the target size is as following: x0＞λ1＞τ2＞τ1＞d; in design process, λ1 and τ1 can value that the objective function value reaches minimum; the d and τ2 need to be selected according to the actual constraint condition under the trend of impact on the target function. After optimization, the system performance is greatly improved.