Abstract: In order to calculate the weak links of the braking module in the power train unit under various operating conditions and improve the structural performance, a three-dimensional model of the braking module is constructed by using the three-dimensional design software SolidWorks, and then modal analysis and static strength analysis are conducted on the modal by using the finite element analysis software ANSYS Workbench. The part with the greatest stress is considered as the weak link, and this part is considered as the key part for subsequent optimization design. Firstly, a finite element model of the brake module is established, and free modal analysis and constrained model analysis are performed to preliminarily identify the weak links. Then, the static strength analysis is carried out to determine the specific location corresponding to the maximum structural stress, identifying the weak link again; and then they are compared and analyzed. Finally, the initial BP model is established, four weight coefficients are introduced and GA is used to explore the optimal combination mode, so as to improve the prediction accuracy of the initial BP model and carry out the muti-objective reliability optimization design of the brake module of the EMU, which provides a theoretical basis for the structural improvement and optimization of the brake module.