Abstract Based on China Household Finance Survey (CHFS) , this paper uses a sharp regression discontinuity model to analyze the impact of air pollution on health expenditure of Chinese residents. There are following findings: (1) Under the influence of air pollution, residents' medical expenditure and health care expenditure increased by 36.35% and 15.94% respectively. (2) The positive impact of air pollution on health expenditure is heterogeneous for different populations, in which rural residents pay less attention to their own health and are less sensitive to air pollution than urban residents, male residents are weaker than female residents, and low-educated residents are weaker than highly educated residents. The research results of this paper have a certain reference value for the product research and development of insurance companies and medical institutions.