Based on the improved STIRPAT model and the affiliation function assessment method, this paper explores the relationship between population aging degrees and carbon emissions in China, divides the population aging into two groups of tendency aging and complete aging for regression investigation, and further explores the impact at the national and regional levels. The results show that, firstly, at the national level, population aging in China has an inhibitory effect on carbon emissions at the present stage. Secondly, at the degree of aging, the effects are different, among which tendency aging can negatively affect carbon emissions, while complete aging is positively affecting carbon emissions, and in the long term, the relationship shows an inverted "U" shape. Thirdly, at the regional level, there are obvious regional differences in these effects. This study helps the government to improve the relevant coping strategies for an aging society.