Manganese is an important trace element that participates in various physiological processes,including skeletal,reproductive,energy metabolism,and normal functioning of the nervous and immune systems.Compared with soluble manganese ions,nano-manganese can maintain the continuous release of manganese ions at the injection site,induce local immune re-sponses,and enhance the cellular uptake of antigens by dendritic cells(DCs),promoting the acti-vation and maturation of DCs in the body.This article reviews the relevant issues of nano-manga-nese from the perspectives of their mechanism of action,preparation methods,functional charac-terization,problems with nano adjuvants,and solutions.The application of nano-manganese as vaccine adjuvants was emphasized and the problems and solutions of nano-manganese were pro-posed.