The invention relates to a classifying device, in particular to a medical ginseng size classifying device. In order to solve the technical problems, the invention provides the medical ginseng size classifying device which is uniform in classifying size, and saves time and labor power. The medical ginseng size classifying device comprises a bottom plate, a large collecting box, a bracket, an air cylinder, a small collecting box, a connecting rod, a button, springs, a large wooden box, a contact block, a small wooden box, a motor, a first driven wheel, a first electric wheel and a first belt, wherein the large collecting box, the bracket, the air cylinder and the small collecting box are sequentially arranged on the bottom plate from left to right; the upper end of a telescopic pole of the air cylinder is connected with the connecting rod in a hinged mode; the left side of the connecting rod is connected with the upper end of the bracket in the hinged mode; the button and the springs are arranged on the connecting rod; and the springs are positioned at the two sides of the button. The medical ginseng size classifying device achieves the effects of classifying uniformly, saving time and saving labor power.