The invention discloses an application of dioscin in preparation of a liver-protecting pharmaceutical preparation. The pharmaceutical preparation can obviously inhibit increase of activity of aminotransferase and lactate dehydrogenase due to medicines (carbon tetrachloride or paracetamol) and alcohol, and reduce the liver indices, thereby performing the liver-protecting function; the pharmaceutical preparation can enhance the activity of SOD, reduce the content of MDA, increase the content of GSH and inhibit liver lipide overoxidation induced by medicines (carbon tetrachloride or paracetamol); and the pharmaceutical preparation can also reduce the content of TG and TC and inhibit the liver steatosis caused by alcohol. The dioscin can be used as the raw material to prepare various preparation formulations for clinic applications according to pharmaceutic related requirements and clinic requirements, such as tablets, capsules, injections, oral liquids, granules and the like. The invention is safe (no toxicity or side effect), convenient, economical and the like.