Abstract: With the continuous increase in train speeds, aerodynamic braking plates have become a critical solution to address insufficient emergency braking forces. To improve the braking efficiency, a perforated braking plate and systematically investigates its design parameters (number, spacing, and diameter of holes) and installation parameters (angle and quantity). A numerical aerodynamic model of a high-speed train equipped with braking plates was established, and the RANS method based on the SST k-ω turbulence model was employed to evaluate the aerodynamic performance of both flat and perforated braking plates. The effects of key parameters on braking performance were analyzed. The findings reveal that the perforated plate significantly enhances braking force compared to the flat plate. The braking force initially increases with the number of holes, hole spacing, and hole diameter, peaking at 8 holes, 135 mm spacing, and 20 mm diameter, beyond which it declines. Optimal braking performance is achieved when the perforated plate is installed perpendicular to the horizontal plane (90°). Under these optimized conditions (8 holes, 135 mm spacing, 20 mm diameter, 90° angle), the aerodynamic drag of the train increases by 4.65%. Additionally, the braking force initially rises with the number of installed plates, reaching maximum effectiveness at 12 plates, and subsequently decreases.