Abstract: Taking the single vehicle hydraulic suspension with nonlinear stiffness and damping as analyzing object, the explicit analytical formulas of vehicle ride comfort were worked out by the method of statistical linearization. Simulink simulation results prove that, the equations are correct. Moreover, according to the fact that body acceleration root mean square value is a concave function on the equivalent damping, namely, there is the only equivalent damping coefficient, which can make the body acceleration root mean square value be the minimum. The results can be used in the nonlinear damping match and strategy implementation of semi-active suspension control.