In order to study the influence of body posture interdependency on suspension control, the model of full vehicle using eight schematic of vehicle plate was analyzed. An approach based on the suspension utility function and a weighted optimization algorithm based on entropy value was presented. A kind of control strategy used in Simulink was designed. Meantime, taking a certain vehicle as an example, a whole multi-body model of vehicle was built. The SIMPACK/Matlab co-simulation in different vehicle speeds under impulse road and snakelike road was tested respectively. Then, the effects of semi-active suspension with fuzzy logical of optimal suspension utility function and other controls were compared. Theoretical analysis and simulation experiment showed that semi-active suspension controlled with fuzzy logical of optimal suspension utility function was practicable. It could improve ride comfort and restrain pitch and roll motion.