Abstract: Milk exosomes are a newly discovered functional vesicles secreted by animal mammary epithelial cells, small vesicles with membrane structure in the diameter of about 30~200 nm, which contain many bioactive substances such as proteins, lipids, and nucleic acids on the surface and inside the membrane. Recent studies have found exosomes with biological functions such as mediating cell communication, promoting cell proliferation, and participating in immune responses. Exosomes can be isolated from the emulsion by centrifugation, chemical, immunoaffinity and identified their morphology, size, specific substances. This article reviews the biological function, three omics studies, separation and identification methods, and aims to provide scientific reference for the research and development of milk source exosomes.