The insufficient supply of family old-age resources and the increasing demand for the elderly are gradually making the aging problem in China a serious social problem. Due to the increasing needs of older adults and to alleviate the shortage, China has witnessed the coexistence of diversified old-age living modes, with the primary modes being community living and institutional living. The health status and life satisfaction of the elderly are different under different living modes. However, there is still no consensus about the relationship between different physical health conditions and the choice of living modes. This limits our understanding of the relationship between old people’s physical health and life satisfaction in different living modes, which needs further study. Therefore, the purpose of the study is to analyze the association among living modes, physical health and life satisfaction, and on this basis, physical health will be regarded as a moderating and mediating variable to further explore whether the influence of living modes on life satisfaction will change according to physical health. The study conducted a questionnaire survey of 300 elderly people in Panzhihua City from February to March 2019. Among them, 150 were community living and 150 were institutional living. The research questions and hypotheses were examined by multiple regression analyses.The main research results of this paper are as follows: 1) there are differences in life satisfaction between the elderly people in the community and those in institutions, and the life satisfaction of the institutional-living was lower than the community-living among the elderly; 2) there is a positive relationship between physical health and life satisfaction, which means that elderly people with better health will be more satisfied with their lives; 3) there is a significant moderating effect the relationship between IADL and life satisfaction: the elderly with a good IADL level in communities have a higher level of life satisfaction, while those with a bad IADL have higher life satisfaction in institutions; 4) the results also show that there is a significant mediating effect of IADL on living modes and life satisfaction, which means that the effect of living modes on life satisfaction is achieved through the mediating effect of IADL.Starting from the elderly people themselves, this paper achieves an understanding their true desire for different living modes, and physical health is used as a moderating/mediating variable for the first time to study whether the influence of living modes on life satisfaction was different due to physical health. Additionally, this study conducted a field survey in Panzhihua, Sichuan Province, using the method of questionnaire analysis. As the experimental development zone of national health-preservation and rehabilitation in China, the results obtained on this basis can more realistically reflect the actual situation.This study has significant reference value for scholars in the field of elderly psychology and professionals such as providers of old-age services. Both communities and institutions should develop services and activities that are beneficial to the elderly’s physical health and pay more attention to their mental health. Furthermore, the government should promote the establishment of long-term cooperative relationships between institutions and local hospitals, and further improving the construction of the pension-related system to provide a strong guarantee for the health of the elderly from an economic perspective.However, there are some limitations in this study. Due to the insufficiency of Chinese domestic theoretical research and relevant scales, this study may ignore some characteristics of Chinese elderly people. The limitations of time and economic conditions also make the sample of this article only reflect the situation of the elderly in a period of time, and there are still some shortcomings in the representation and wide-scale promotion. Future research can use more diverse research methods, strengthen theoretical support, and expand the sample size to make more meaningful points to the research conclusions.