The invention mainly discloses a cooling device, which is assembled on a vehicle body for lowering the temperature of a brake system. The cooling device comprises a cooling body, a fluted disc and a fan group, wherein the cooling body is provided with an action part and a cooling part, and the cooling part is provided with an air outlet and an air inlet; the fluted disc is arranged on the action part, the periphery of the fluted disc is provided with a tooth part, the center of the fluted disc is provided with a positioning part, and a hub end is assembled on a positioning part; the fan group comprises a fan and a gear assembly, the fan is pivoted to the cooling part, and the gear assembly is assembled on the center of the fan and is mutually meshed to act with the tooth part of the fluted disc; the fluted disc is driven to rotate by the rotary movement of the hub, the fluted disc is linked with the gear assembly to drive the fan to rotate, so that cold air enters from the air inlet and is discharged from the air outlet, and therefore, an oil pressure calipers cooling effect is improved.