In order to avoid modifying vehicle body repeatedly in the later design stage, the multi-objective optimization module in vehicle concept design intelligent CAE system (VCD-ICAE) was developed. A multi-objective optimization algorithm was designed with the objectives of body structure stiffness and modal. The whole body structure performance could be improved on the premise that mass of body didn’t increase. The basis for realization of body lightweight in concept design stage was provided, so the time and cost were economized. Combining concept design process of a concrete body model, the multi-objective optimization was carried on. The bending stiffness, torsion stiffness, first bending frequency and first torsion frequency of body were increased. The validity and correctness of the proposed multi-objective optimization module was verified.