The four-wheel electric vehicles drive the vehicle independently through the in-wheel motor, which causes the electromagnetic force output fluctuation directly acts on the wheels and the suspension, resulting in deterioration of the vehicle's dynamic performance. The Fourier series method was adopted in this research to develop an in-wheel motor-electric vehicle (IWM-EV) co-model with active suspension.And then, a co-operative parameter optimization via (multi-objective particle swarm optimization) MOPSO was proposed to weaken the negative vibration effects caused by electromechanical coupling in in-wheel motor system. The simulation results has testified its effectiveness.