Abstract: In order to achieve the best utilization effect of chassis space, a certain model innovatively sets the installation point of battery pack on the chassis structural parts, and the production line feedback the interference risk of accidental installation of wrong holes in the small-batch production verification stage. In this paper, the 3DCS software is used to establish a simulation model of battery pack matching with the car, and simulation analysis on the problem scenario is also conducted. The results show that the analysis values are basically consistent with the actual statistical results, which proves that the model is real and reliable. In order to effectively solve the problem of assembly interference, it is recommended to adopt measures such as single side and double limit pin to improve the robustness of the assembly positioning of the torsion beam mounting bracket, which can significantly reduce the 6STD value, and at the same time optimize the size specifications of the parts with high contribution on the dimensional chain link, further reducing the risk of assembly mis-holes. After the above optimization measures are applied in actual production, through continuous monitoring about 1 000 off-line vehicles, it is shown that no assembly problems such as battery pack installation wrong holes occurred, thus the improvement effect is obvious, and it can effectively meet the production line production requirements.