Probiotics is living microorganisms that is beneficial to host health, and postbiotics is inanimate microorganisms and/or their components that confers a health benefit on the host. Based on the research results of postbiotics in recent years, we reviewed the functional characteristics of postbiotics in regulating immunity, relieving allergic symptoms, adjusting gastrointestinal function, anti-oxidation, anti-inflammation, falling blood glucose, preventing dental caries, anti-tumor, and lowering blood pressure. Concurrently, the possible mechanism of postbiotics is also summarized. Compared with live bacteria, postbiotics has the advantages of safety, stability, easy storage and transportation, so that the development potential and application prospect of postbiotics are very broad in the field of food and medicine.