Handling stability is one of the important characteristics to evaluate the vehicle performance. This paper presents the modeling, simulation, optimization of handling for a heavy truck. A detailed heavy truck model was built by ADAMS, which consists of the frame, suspension system, steering system, wheel, the cab, etc. The simulation results fit the experiment data very well, which shows that the dynamic model can accurately predict the performance of the vehicle by modeling and simulation. Handling simulation was carried out to show how the parameters influence the performance of the handling. The optimization was carried out based on the simulation results. The experiment data shows that the handling of the heavy truck such as on center handing, steering returnability, steering-effort has been significantly improved.