Marine organisms are rich in ω-3 polyunsaturated fatty acids(PUFAs)， especially Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA). It plays an important role in preventing cardiovascular diseases， inhibiting cancer， anti-inflammatory， and promoting brain development， so it has great potential in the health care products and pharmaceutical industries. This article first briefly describes the dietary structure of ω-3 PUFAs and their different biological sources in the ocean， and then compares the differences in metabolism of ω-3 PUFAs with different structures in detail， and finally summarizes the isolation and purification methods of ω-3 PUFAs， with a view to ω-3 PUFAs provide theoretical support for further exploration and development in the fields of functional food and medicine.