A traditional Chinese medicine immunopotentiator prepared from mulberry leaves polysaccharide and eucommia polysaccharide. The immunopotentiator can stimulate proliferation of chicken lymphocytes in vitro. When used together with newcastle disease vaccine to immunize chickens, the immunopotentiator can increase serum antibody titer, promote proliferation of lymphocytes, and enhance cellular immunity and humoral immunity of the chickens. When used together with porcine productive and respiratory syndrome vaccine to immunize piglets, the immunopotentiator can increase the serum antibody titer. When used together with the porcine productive and respiratory syndrome vaccine to immunize layers, the immunopotentiator can increase porcine productive and respiratory syndrome virus yolk antibody titer and improve immune effects of the vaccine.