The invention discloses a motor-driven tipping device of a slag pot car and a working procedure thereof. The motor-driven tipping device comprises a worm reduction gear, a moment idler wheel, a guiding rail, a planet cycloid pinwheel reduction gear and a chain and sprocket device, wherein the worm reduction gear is connected with a trunnion of a slag pot supported frame by a retaining plate and suspended on the trunnion; the planet cycloid pinwheel reduction gear is arranged at the upper part of the worm reduction gear and is connected with the worm of the worm reduction gear by the chain and sprocket device; and the moment idler wheel is fixed at the lower part of the worm reduction gear and is arranged in a guide rail. The method comprises two steps of deslagging and returning. Since the invention adopts the worm reduction gear and the moment idler wheel for replacing two parallel screws and nut skid frame driving devices, transmission mechanisms are simplified and the transmission efficiency is increased. The electromotor of the 24m<3> motor-driven tip-over slag pot car only needs 11kw power; compared with the power of the original motor-driven tip-over slag pot car, the power is reduced by 19kw, thus greatly reducing the energy consumption.