Vehicle rollover represents one of the most dangerous traffic accidents in the world. To improve the antirollover capability of a vehicle, we established an improved rollover model with a particular focus on the effects of independent suspensions and the lateral deformation of the tire. Based on this model, we further developed a new method to mitigate the rollover occurrence by adjusting the stiffness of the spring and the damping coefficient of the damper. Through simulation tests with a brand of SUV, we demonstrated that these adjustments improved the mitigation control as evidenced by better confined steady value and decreased overshoot of the roll angle.