A powder allotting device comprises a supporting device, a coupling device, and a separating device. The supporting device is a base of the powder allotting device, and the supporting device is coupled to the separating device by the coupling device. The a separating device further comprises a rotary plate with a curved grooved structure, a plurality of movable valves, a scraper, and a cylinder with a plurality of T-shape grooves, and a plurality of slices. The plurality of slices are inserted into the T-shape grooves and enter the curved grooved structure, moving up and down the T-shape grooves.