The shortage of fishmeal is an urgent problem to be solved in the research of aquaculture nutrition. Given that fish by-product accounts for more than 60% of processed fish biomass, more efficient use of marine protein from fish by-products and improving their nutritional value are important ways to alleviate fish meal shortage at present. Fish protein hydrolysate, which mainly contains a mixture of small peptides and free amino acids, is produced by hydrolyzing fish by-products. More and more studies have proved that fish protein hydrolysate has a beneficial effect on the growth performance of aquatic animals. This paper reviews the preparation of fish protein hydrolysate, its nutritional characteristics and study on aquaculture nutrition. This study systematically discusses the research results of fish protein hydrolysate in the field of aquaculture nutrition in recent years, and proposes further research directions in aquafeed, in order to provide reference for the study of fish protein hydrolysate in aquaculture nutrition and aquafeed application.