Exosomes, as small molecule extracellular vesicles secreted by a variety of cells, play an important role in the pathological process of Alzheimer's disease by transporting a variety of bioactive substances such as microRNA. Studies have shown that the expression of exosomal microRNA changes in the early stages of AD patients, and exogenous injection of mesenchymal stem cell-derived exosomal microRNA can improve the learning and memory ability of AD animal models. This paper reviews the research progross of exosomes in early screening and treatment of Alzheimer's disease.