The invention discloses a device for maintaining adhesion coefficient of a wheel rail. The device at least comprises a bogie flashing board, a motor, a rotating shaft, a disk brush, an air knife, an air duct, an electric heating device, a fan, a lifting platform and a transmission device, wherein the bogie flashing board is mounted on the outer side of a motor car bogie wheel set; and the rest equipment is mounted in an equipment cabin above a power shaft. When in rainy, snowy, frost and heavy fog and wet days or when attachments such as floating dust, oil contamination and leaves are on a rail surface, a control system controls the transmission device so that the disk brush and the air knife drop to the rail surface from the equipment cabin; and the motor drives the disk brush on the rotating shaft to rotate at high speed, the leaves, the oil contamination, accumulated water, accumulated snow and other attachments on the rail surface are removed from the rail surface, high-pressure air generated by the fan is sprayed out from the air knife at high speed, residual water is blow-dried instantly, so that the rail surface is always in a dry state, stable adhesion coefficient between wheel rails is ensured, and a high-speed train can safely and stably run at high speed around the clock.