Alzheimer's disease (AD) is a common and highly disabling irreversible degenerative disease of the central nervous system, with characteristics as progressive cognitive impairment, memory loss, and behavioral disturbances. Cognitive impairment in AD, being closely associated with amyloid beta-protein (Aβ) deposition, Tau hyperphosphorylation and neuroinflammation, affects the quality of life of patients. Currently, the exact cause of AD remains unclear, and effective treatment options still lacks. In recent years, stem cell-derived exosomes have garnered widespread attention due to their unique biological properties and crucial role in intercellular communication. These exosomes can carry various bioactive molecules, such as proteins, lipids, and RNA, playing significant roles in central nervous system degenerative diseases. Therefore, this article primarily describes the biogenesis, biological characteristics, and advantages of stem cell-derived exosomes, and summarizes their current applications and future prospects in cognitive impairment in AD, aiming to provide new insights for AD treatment.