This study aims to identify the role and pathways through which social class plays a part in the impact of the social environment on residents' health. Using data from the China General Social Survey 2021, we analyzed a sample of 2715 participants to assess the role and pathways of social class in the influence of the social environment on residents' health. We employed the Ordinary Least Squares model to quantify the impact of the social environment on residents' health and utilized the Karlson-Holm-Breen method along with the construction of product terms to estimate the mediating and moderating effects of social class. To address endogeneity, we conducted robustness tests using the instrumental variable method. Our findings indicate that in the process of the social environment's impact on residents' health, social class acts as a moderator, functioning with an approximate effect of 20%. In terms of the pathway of action, this moderating function is realized by exerting an influence on residents' mental health. When analyzing the social determinants of health, it is necessary to consider the significant role played by social class and to pay more attention to the potential impact of the mental health of different social classes on their overall health.