The invention discloses a biological feed additive for pigs for enhancing immunity and improving feed utilization rate, and belongs to the field of feed additives. The additive is prepared from fermented Chinese medicine herb powder, bupleurum polysaccharide, herba elsholtziae powder, ginger powder, mulberry powder, pumpkin peel powder, compound vitamin, taurine, ferrous lactate, manganese sulfate and carriers, wherein the carriers are defatted rice bran and bentonite. According to the additive, the pig immunity can be effectively enhanced, the pig morbidity can be reduced, the feed conversion ratio also can be lowered, the feed utilization rate can be increased, meanwhile, growth of the pigs is promoted, the feeding time is advanced, the feeding period is quickened, the feeding cost is reduced, the feeding benefits are increased, and the application prospect is wide.