Oxaquinic acid, also known as oxycyclooxaquinic acid, ocisolin acid and olinic acid, is a second-generation quinolinone fungicide. It is white with yellow and white columnar crystal or crystalline powder at room temperature, odorless and tasteless. It has strong antibacterial effect on gram-negative bacteria and part of positive bacteria, and has no cross-resistance with antibiotics. However, it has no antibacterial effect on mycobacterium Chemicalbook and mycobacterium tuberculosis, and has the advantages of low dosage and good antibacterial effect. It is mainly used to treat bacterial diseases of fish and shrimp. Aquaculturists believe that it is one of the ideal drugs for the treatment of aquatic animal diseases, and has quite strong antibacterial activity against fish pathogens such as Vibrio eel and aeromonas hydrophila.