Abstract: With the advent of aging society, the skeletal muscle volume and muscle strength of the elderly are reduced, and they are prone to sarcopenia. Sarcopenia has caused a lot of inconvenience to the life of the elderly. At present, the symptomatic medical treatment for sarcopenia is not perfect. It is necessary to understand its pathogenesis and treatment measures. Protein supplementation, as the most healthy, effective and convenient method, has attracted people's attention. This paper summarizes the pathogenesis and current prevention and treatment methods of sarcopenia, the significance of protein action and sarcopenia and the role of protein in the prevention and treatment of sarcopenia are clarified. It lays a theoretical foundation for the application of protein in different ways and the treatment of sarcopenia.