Abstract: During the pre-operational dynamic debugging process of CRH5G EMUs, the train was affected by the contact pressure of some railway sections, and the electric brake function was abnormal, in the process of speed adjustment on the long ramp, the braking force was completely applied by the air brake, which caused the brake discs and the brake pads to be in abnormally high temperature condition for a long time, thereby, the reliability decreased and prone to failure. This paper aimed at the existing problems, optimized and upgraded the scheme of brake force distribution by optimizing the logical structure of brake force distribution. The calculation and analysis of the actual load and the heat load of the brake disc prove that the optimized scheme can effectively reduce the braking system failure, save energy, reduce the consumption, and continuously improve the energy efficiency of high-speed trains.