Abstract: In order to study the performance indexes of the main load-bearing parts of the car body under the frontal 40% overlap rate impact, as well as the crashworthiness of the car body after repair, the finite element model of the collision between the whole car and the deformable barrier at a speed of 64 km/h was established by combining the software of HyperWorks and LS-DYNA, and simulations were carried out. Based on the simulation results, the force transmission paths of the main load-bearing parts and the absorption of impact energy are analyzed during the collision. The crashworthiness of the car body is indirectly analyzed by the acceleration at each seat of the passenger compartment, the intrusion of the front enclosure and the time curve of the bending angle of the upper part of the A-pillar. Through the ANSYS software, modal analysis and fatigue analysis were conducted before and after the repair of the main load-bearing parts of the car body in the case of collision damage, and it was concluded that the fatigue life of the repaired car body was lower than the original value, which can provide theoretical references for the structural optimization of the car body after repair.