The present invention discloses a cylindrical motor housing. The motor housing is a cylindrical body with an inner chamber, a plurality of external insertion pieces are arranged at the outer surface of the motor housing, a horizontal installation plane is arranged at the exterior of the motor housing, and housing installation parts are arranged on the motor housing and arranged at two sides of the plane. The thermal conduction is generated between the installation plane and a fixed plane to ensure the heat radiation efficiency of the motor housing. Compared the connection surface with the leg in the prior art, the housing material consumption is small, and the housing cost is reduced. Besides, the housing installation parts are able to enhance the motor assembling stability. The motor housing accords with the development trend of equipment miniaturization.