Impurity separation unit

The utility model relates to the technical field of traditional Chinese medicine decoction piece preparation equipment, in particular to an impurity separation unit which comprises a separation machine box, a collecting box is arranged on the front side of the separation machine box, a supporting plate is fixedly installed on the top face of the separation machine box, a separation assembly is arranged on the supporting plate, and the separation assembly comprises an air cylinder fixedly installed on the supporting plate. A mesh filter plate is arranged at the tail end of a telescopic shaft of the air cylinder, blocking frames with U-shaped sections are fixedly installed on the three side edge portions of the mesh filter plate, the discharging assembly comprises a discharging hopper fixedly installed on the inner wall of the separator box, and a flapping assembly is arranged at the position of a discharging hole. The beating assembly comprises a driving motor fixedly installed on a plate body on one side of t