The utility model discloses a quantitative discharging device. Including a discharge chamber, the discharging chamber is provided with a feeding port and a discharging port. a central shaft which axially penetrates through the discharging chamber is arranged in the discharging chamber; a plurality of separation blades are fixed to the center shaft and distributed on the center shaft in a radial equal-central-angle mode, one end of the center shaft extends out of the discharging chamber and extends outwards, and the part, extending outwards, of the center shaft is connected with an intermittenttransmission mechanism; the intermittent transmission mechanism comprises a base, a power source and a linkage fork. The center of the base is fixedly installed on the center shaft. A plurality of pins are arranged on the base in the circumferential direction with the center shaft as the center. A fork opening is formed in one end of the linkage fork, a sliding groove is formed in the other end of the linkage fork, the sliding groove is formed in the center shaft in a sleeving mode, the power source drives the linkage fork to do linear reciprocating motion along the sliding groove, meanwhile,the fork opening of the linkage fork is driven to enter or be away from the pin, and the linkage fork drives the base plate to rotate intermittently.