First front crash for a mini-MPV was simulated and correlated with its test using finite element method, and the vehicle structural crashworthiness was optimized based on the test data and the model. Then under the premise of satisfying the requirement of crashworthiness and basically remaining its stiffness, modal and so on, this paper provided a method to maximum reduce components’ masses to light weight and control cost. Finally, a frontal crash test of this optimized vehicle was performed to verify that the structure optimization and lightweight method is feasible.