Collagen is a biopolymer, the main component of animal connective tissue. It is also the most abundant and widely distributed functional protein in mammals, accounting for 25% to 30% of the total protein, and even up to more than 80% in some organisms. . Animal tissues derived from livestock and poultry are the main way for people to obtain natural collagen and collagen peptides. However, due to related livestock diseases and certain religious beliefs, people have restricted the use of terrestrial mammalian collagen and its products. Now they are gradually turning to the ocean. Developed in biology. The European Food Safety Authority (EFSA) has confirmed that even collagen derived from animal bones has no possibility of infection with mad cow disease and other related diseases. Due to differences in amino acid composition and cross-linking degree, the rich collagen contained in aquatic animals, especially their processing wastes - skins, bones and scales, has many advantages that livestock collagen does not have. In addition, it comes from the ocean. Animal collagen is significantly better than the collagen of terrestrial animals in some aspects, such as low antigenicity and hypoallergenicity. Therefore, aquatic collagen may gradually replace terrestrial animal collagen. There are many types of collagen, and the common types are type I, type II, type III, type V and type XI. Collagen has been widely used in food, medicine, tissue engineering, cosmetics and other fields because of its good biocompatibility, biodegradability and biological activity.