The goal of this thesis is to develop an active front steering(AFS) control system which can apply to ordinary vehicle. This AFS control system stabilizes the driving vehicle and reduces the possibility of rollover. This thesis uses magic formula tire model and constructs a vehicle model with eight degrees of freedom to study the dynamic behavior of the real driving vehicle. This thesis constructs a vehicle model with three degrees of freedom and eight degree of freedom, compare with two vehicle model, we adopt eight vehicle model in this thesis. The advantages of PI controller are low cost and easy to modify, so this thesis adopts PI controller as the control strategy. This study uses four simulate methods and compares the simulated results to develop the AFS control system which can apply to ordinary vehicle.