The invention relates to a feed additive for relieving the fatty liver of pseudosciaena crocea as well as a preparation method and application of the feed additive, and belongs to the field of feeds.Each 100 parts by weight of the feed additive comprises 0.8-4 parts of plant extracts, 0.2-1 part of rare earth-chitosan chelate, 2-10 parts of haw powder, 1-5 parts of radix puerariae powder, 3-15 parts of alpha-zinc sulfate, 1-5 parts of leucine, and the balance of a carrier, wherein the plant extracts comprise a radix scutellariae extract, a fructus perillae extract and a macleaya cordata extract. The feed additive is safe, harmless, low in consumption, low in cost and stable in effects. The preparation method of the feed additive comprises the following step of mixing the components of thefeed additive. The preparation method is simple, and the condition controllability is good. The feed additive is applied to preparation of the feed for the pseudosciaena crocea and is used for feeding the pseudosciaena crocea, so that the generation of the fatty liver of the pseudosciaena crocea can be effectively relieved, the organism immunity of the pseudosciaena crocea can be improved, and the body color can be improved.