Disclosed is a motor damping device. A half-cylinder-shaped rotator is fixedly installed at the bottom of a fixing frame. The end, stretching out of a supporting base, of a right guide rod is fixedlyconnected with a transmission frame, a first rack parallel to the axis of the rotator is fixedly arranged on the transmission frame, a first gear is meshed with the first rack, a driving bevel gear isinstalled on a first gear shaft and meshed with a driven bevel gear, the driven bevel gear is installed on a base through a bevel gear shaft and a bearing pedestal, the bevel gear shaft and a first friction disc shaft are connected so that power can only be transmitted to a first one-way transmission mechanism of the first friction disc shaft from the bevel gear shaft, and the first friction discshaft rotates so that the first friction disc and a second friction disc can rotate relatively. Due to relative rotation of the two friction discs, vibration is converted into friction heat to be consumed, the vibration amplitude is lowered, vibration of other parts is lowered, and the service life of the parts is prolonged. Noise is greatly lowered, and the working environment of a factory is improved.