In response to the increasing aging problem that China is facing, this study aimed to investigate the impact of social health on the mortality risk of the Chinese older adult population. In this paper, we used the data from “The Chinese Longitudinal Health Longevity Survey (CLHLS)-Longitudinal Data (2008–2018)” and applied the Cox proportional hazard model to investigate the effects of three dimensions of social health on the risk of death among older adults in China. The study found that: (1) The three dimensions of social health have a positive effect on the mortality risk of older adults. (2) Among those three dimensions, social activities had the most significant effect on older adults. The effect of social support and social network on the mortality risk of older adults are basically similar. Moreover, social activity, social support, and the social network had no significant effect on the young-old’s mortality risk. (3) In order to address the problem of data censoring, the Cox proportional hazard model can be used, whereas demographic characteristics, health status, and health behavior components are selective to society. This study enriches social health research in China and promotes the development of social health research from theory to practice. Moreover, it has obvious advantages in terms of economics and feasibility for achieving mortality risk reduction through improving the social health of older adults and building a healthy aging society.