The invention relates to a novel decelerating device which comprises a motor, a curved-tooth bevel gear, an output shaft and a worm. An output shaft of the motor is engaged with the curved-tooth bevelgear through an engaging mechanism, and the worm is engaged with the curved-tooth bevel gear. A worm wheel is arranged on the worm, and a decelerating mechanism is arranged between the worm wheel andthe output shaft. According to the novel decelerating device, a transmission structure is reasonable in mode, lifting precise positioning and safe self-locking are accurately achieved, the service power is small, the bearing capacity is large, energy conservation is achieved, operation is easy, and the automation degree is high.