By using the data from the China General Social Survey (CGSS) 2021, this study establishes a structural equation model to investigate the impact mechanism of lifestyle on the subjective well-being of the elderly. The results show a lot. Lifestyle has a positive direct impact on subjective well-being, meaning that the elderly who have a richer lifestyle may get a higher subjective well-being. Health status plays a mediating positive role between lifestyle and subjective well-being, meaning that lifestyle can enhance the subjective well-being of the elderly by improving their health status. On the first half of the mediation effect, class identity has a significant negative moderating effect which indicates that the impact of lifestyle on health status maybe weaker, if the elderly have a higher the social class. This paper proposes some suggestions. Focusing on and improving the lifestyle of the elderly, perfecting the pension and medical service systems, and enhancing the well-being of the elderly.