Fish feed additive as well as preparation method and application thereof

The invention discloses a fish feed additive as well as a preparation method and an application thereof. The additive contains 2-5 parts of an isatis root extract, 2-5 parts of a baical skullcap rootextract, 2-5 parts of an astragalus root extract, 2-5 parts of a honeysuckle stem extract, 2-5 parts of angelica root extract and 1-4 parts of a licorice root extract. The additive is a pure plant ingredient, reduces the risk caused by chemical material pollution, is beneficial to disease prevention of fish and can increase the survival rate, raise the secretion level of digestive enzyme of the fish, promote healthy growth of the fish, substantially improve the economic benefits of the fish culture industry and promote healthy development of the industrial chain. Tests verify that the additivecan prevent and treat the disease problem in the grouper culture process effectively and contribute to further development of the grouper culture industry after use. 本发明公开了种鱼饲料添加剂及其制备方法和应用，所述添加剂中含有板蓝根提取物2～5份、黄芩提取物2～5份、黄芪提取物2～