The invention discloses a medicine for preventing or treating fatty liver and application thereof. The medicine can effectively prevent or treat pimelosis of nonalcoholic fatty liver, repair oxidative injury of liver tissue and maintain the functions of the liver. The medicine contains an effective dose of oroxin A and optionally contains a pharmaceutically acceptable carrier and/or excipient, and the dosage forms of the medicine include tablets, orally disintegrating tablets, sustained release tablets, granules, capsules, freeze-dried powder injection, pills, suspension, syrup, emulsion or injection.