Abstract: In order to investigate the influential factors of a vehicle's overriding condition in a crash, a 2D collision dynamics model that considers the dynamic coupling relationship between anti-climbers was set up. Based on this model, a geometric searching algorithm for anti-climber contact was presented, and a method for calculating the anti-climber's longitudinal resistant force based on energy conservation law was developed. Expressions of the anti-climber resistant force and torque were derived taking into account the influence of the large plastic deformation and dynamic factors. In addition, a numerical example was provided to simulate the dynamic characteristics of the anti-climber. The results show that the meshing degree between ant-climber teeth has a close relation with the maximum absolute and relative rotation angles of the anti-climber. The maximum absolute rotation angle of anti-climber teeth can be reduced by decreasing the longitudinal resistant force and the energy absorption length and increasing the bending rigidity of the anti-climber device. The maximum relative rotation angle of anti-climber teeth increases with the energy absorption length. With the bending rigidity of the anti-climber increasing, the maximum relative rotation angle shows a trend of first increase and then decrease, but the longitudinal resistant force of the anti-climber has no significant effect on the relative rotation angle. Compared with the traditional finite element method, the proposed method can reduce the calculation time by 10% .