The side of the car is a relatively weak part in the body. It is particularly important to optimize the stiffness and strength of the side parts to enhance the collision resistance of the car side. Establish a side impact finite element model for a domestic SUV, and conduct a side impact simulation according to the regulations, and analyze the energy in the system to verify the effectiveness of the model. By comparing the values of the speed, intrusion amount and acceleration of the key points before and after, based on the basis of the test design and the response surface method, the scheme for the improvement of the side impact resistance is proposed and the effectiveness of the response surface method in improving the impact resistance of the structure is verified.