Abstract: With the in-depth study of the molecular pathological mechanisms of psychiatric diseases, exosomes, as important carriers of intercellular signal transmission, have gradually become a research hotspot. Exosomes belong to extracellular vesicles at the nanoscale. With their unique biological characteristics, they play a key role in intercellular communication and can promote targeted delivery. Meanwhile, exosomes have multiple administration routes, providing new options for the diagnosis and treatment of psychiatric diseases. This review summarizes the research progress of exosomes in the diagnosis and treatment of psychiatric diseases, aiming to provide some reference for related research and application.