With the exacerbation of the aging population trend, a series of neurodegenerative diseases caused by brain aging have become increasingly common, significantly impacting the daily lives of the elderly and imposing heavier burdens on nations and societies. Brain aging is a complex process involving multiple mechanisms, including oxidative stress, apoptosis of damaged neuronal cells, chronic inflammation, and mitochondrial dysfunction, and research into new therapeutic strategies to delay brain aging has gradually become a research focus in recent years. Mesenchymal stem cells (MSCs) have been widely used in cell therapy due to their functions such as antioxidative stress, anti-inflammation, and tissue regeneration. However, accompanying safety issues such as immune rejection, tumor development, and pulmonary embolism cannot be avoided. Studies have shown that using exosome derived from mesenchymal stem cells (MSC-Exo) for the treatment of neurodegenerative diseases is a safe and effective method. It not only has the therapeutic effects of stem cells but also avoids the risks associated with cell therapy. Therefore, exploring new therapeutic strategies to delay normal brain aging from the mechanism of MSC-Exo in the treatment of neurodegenerative diseases is feasible. This review summarizes the characteristics of MSC-Exo and their clinical progress in the treatment of neurodegenerative diseases, aiming to explore the possibility and potential mechanisms of MSC-Exo in reversing brain aging.