The design process of controller for active suspension employed by a pickup vehicle based on the co-simulation was presented. First, a detailed multi-body dynamic model of the vehicle was established by using ADAMS/VIEW software package; second, a stochastic controller was designed for active suspension system and worked out by means of Matlab/Simulink, the proposed control algorithm was integrated with the multi-body dynamic vehicle model and the co-simulations could be performed repeatedly until a satisfactory controller was achieved, the system was compared with a conventional passive one. Simulation results showed that the proposed active suspension considerably improved both the ride and handling performance of the vehicle.