Abstract: The train braking device includes an air brake controller in which a plurality of friction coefficients corresponding to a brake command and a brake initial velocity are stored, an electropneumatic conversion valve that converts a pressure control signal transmitted from the air brake controller into a pneumatic signal, a relay valve that generates a predetermined brake cylinder pressure corresponding to the pneumatic signal, and a brake cylinder that controls brake shoes according to the brake cylinder pressure, wherein the air brake controller generates the pressure control signal based on the friction coefficients corresponding to the brake command and the brake initial velocity.