With the high speed electric multiple unit brake disc system as the research object,the structure factor was proposed to analyze the surface temperature distribution of the brake disc.The thermal mechanical coupling analysis was respectively carried out for three different shapes and three different arrangement of brake pad structure by using the finite element software.The finite element analysis results verified that the structure factor can be used to predict the change of temperature field and stress field.The results show that the change of temperature field and stress field of brake pads can be characterized by the structure factor of brake pads for different shapes and different arrangement,and by adjusting the brake pad arrangement,the brake disc temperature field and stress field distribution can be improved.The thermal distribution and the stress distribution of the brake disc are interrelated,but the effect of heat change on the stress change of the brake pad is very small.