The invention provides a feed additive capable of reducing diarrhea rate of piglets and relates to a feed additive for piglets. The feed additive can be used for solving the high diarrhoea rate in existing piglet production. The feed additive consists of tuckahoe, white atractylodes rhizome, rhizoma optidis, dried ginger, costus root, licorice, angelica, white peony root, ligusticum chuanxiong hort, radix scutellariae, ledebouriella seseloides and tuber pinellia. Traditional local herbal materials are reasonably selected for the feed additive according to the physiologic characteristics of piglets, to that the feed additive has the efficacies of clearing away heat and toxic materials, eliminating dampness and relieving diarrhea, invigorating vital function and regulating the flow of qi, is capable of obviously relieving the diarrhea symptoms of the piglets, and further has the characteristics of wide herbal material source, multiple functions, no residues, no toxic or side effects and the like. The preparation method is simple, practical, safe and reliable. 1% of the feed additive is added into a basal ration for the piglets, and the feed additive and the basal ration are uniformly stirred so as to be used for directly feeding the piglets. The feed additive is applicable to the piglets of native pigs, foreign varieties of pigs, wild pigs and the like.