Based on particle swarm optimization (PSO) algorithm, a fuzzy self-tuning controller parameters optimization method was developed. With the co-simulation of Carsim and Simulink, typical optimized working conditions were selected. The controller’s scaling factor value and the position of membership function shape points were randomly selected to ensure the controller optimal performance. The controller was also reconstructed. Optimum remembering points and contrast mechanism among these points were working in PSO algorithm with the optimum target function. The actual vehicle experiments were carried out under typical working conditions. The experiment results showed that the optimized controller had good control performance, which could decrease the design workload of performance matching between the adaptive cruise control and test vehicle. 