Brake device, brake system and vehicle

The invention provides a braking device, a braking system and a vehicle, the braking device comprises a pipeline collecting shaft and a braking disc, n overflowing cavities which are mutually independent are formed in the pipeline collecting shaft, and n is an even number larger than or equal to 4; a connecting hole formed in the axial direction of the brake disc is formed in the middle of the brake disc, n/2 refrigerant circulating channels are formed in the brake disc, channel openings of the refrigerant circulating channels are all located in the hole wall of the connecting hole, and the end of the pipeline collecting shaft is embedded into the connecting hole. The side wall, located in the connecting hole, of the pipeline collecting shaft is provided with n first overflowing holes in one-to-one correspondence with channel openings of the refrigerant circulating channels, the n first overflowing holes correspond to the n overflowing cavities in a one-to-one correspondence mode, and the side wall, located o