The utility model relates to the technical field of electrical equipment, it discloses a ring main unit, including the first cabinet body, set up the internal second cabinet of the first cabinet body and with first cabinet body articulated cabinet door, the first cabinet body and second cabinet side wall, the equal spaced apart setting in top surface and bottom surface, the internal a plurality of baffle that is equipped with of second cabinet, second cabinet sinistron lateral wall is equipped with the guide duct respectively in the wall of right side, first cabinet body top is equipped with the fan, guide duct one end with said fan is connected, the guide duct other end is sealed, second cabinet sinistron lateral wall is equipped with the shower nozzle respectively on the wall of right side, said shower nozzle with said guide duct communicates with each other, first cabinet body bottom is equipped with the entrance hole, the first cabinet body is equipped with the louvre respectively on the lateral wall of second cabinet body back. The utility model discloses the structure is taken up an area of for a short time, and simple structure is compact, and operating maintenance is convenient, and the shielding is high, and the security is high, and is with low costs, life