Abstract:In the development of vehicle passive safety,the energy gradient of the thinwalled beam energy absorbing structure is usually adopted to satisfy the energy absorption requirements under different collision conditions. Sufficient and stable deformation will help to improve energy absorption efficiency of the structure and ensure good maintenance economy. The reasonable energy absorption was considered as the design target for the frontal structure of medium and large passenger cars in frontal crash condition,by means of theoretical calculation and finite element simulation analysis, the preliminary design scheme was determined and the optimum design of structural stiffness matching was carried out on the basis of that.The results show that the stiffness matching method of the front end of the vehicle based on the energy absorbing target can meet the requirement of energy absorption, and the stiffness matching between the structures is better; under different conditions of collision, it can deform according to the ideal mode and meet the design requirements.