In order to improve vehicle ride comfort and decrease dynamic tire load on road, a 4-DOF pneumatic suspension model for a half vehicle model was established. Based on this model, a general genetic algorithm was used to solve the multi-objective optimization problem. Besides, an improved adaptive multi-objective genetic algorithm (MOGA) was proposed and applied to optimize the suspension parameters of heavy vehicle. Compared with the former, the effective value of the vehicle body's vertical acceleration and the front/rear-wheel dynamic load decreases by 10%, and the improvement of objective value decreases remarkably by 57.03%. It is shown that using this method proposed in this paper not only enhance the ride stability but also reduce dynamic tire load on ground, which further verify the effectiveness and feasibility of the improved adaptive MOGA.