Abstract: As an immune enhancer, adjuvant can non-specifically improve the body's immune response to specific antigens. When the adjuvant is injected into the body together with or in advance of the antigen, it is a type capable of strengthening the humoral immune response or modulating the immune response against the antigen. Squalene, a triterpenoid with an immune-enhancing effect, can stimulate the maturation of plasma cells, produce a large number of antibodies, and enhance human humoral immunity and cellular immune response. It is widely used in vaccines and drug carriers. Squalene-based emulsion adjuvants such as MF59, AS03 and AF03 have been developed and widely used in influenza vaccines. By comparing the similarities, differences and application characteristics of squalene and other adjuvants, this paper summarizes the application status of squalene in new vaccine adjuvants, with a prospect of the application of squalene adjuvants from the perspective of technical improvement.