The invention discloses an efficient heat dissipation electric cabinet which comprises an electric cabinet body, the front side of the electric cabinet body is movably connected with a cabinet door, a plurality of ventilation holes are formed in the upper portion of one side of the electric cabinet body, the rear side of the electric cabinet body is fixedly connected with a back frame, and one end of the back frame is fixedly connected with a sliding block. The electric control box has the advantages that when the electric control box normally operates, the electric control box is located at a high position and is not prone to being touched by non-professional personnel by mistake, the electric control box is safe for the personnel and the electric control box, meanwhile, water enters the electric control box located at the high position when the electric control box overflows, the electric control box is far away from the ground, and the electric control box has good moisture-proof performance; when the temperature of the electric control box is high, the row plate drives the top column to advance, the sealing plate is jacked upwards, the ventilating duct is opened, at the moment, the output end of the heat dissipation fan directly faces the ventilating hole and blows air towards the ventilating hole, air rapidly flows through the interior of the electric control box and flows out of the ventilating duct, efficient heat dissipation is conducted on the electric control box, and therefore the electric control box can be automatically and further cooled when the temperature is high; and the design of few ventilation openings is met, and the moisture-proof requirement is met.