The health of older adults is crucial for the overall health of the entire life cycle. Based on population sampling survey data and census data from 131 prefecture level units in the Yangtze River Economic Belt (YREB) during 2010–2020, this study used exploratory spatial data analysis, geographical detector, stepwise regression analysis, and GTWR model to analyze the spatiotemporal pattern and influencing factors of the health level of older adults in the YREB. The results show that the health level of older adults in the YREB slightly increased from 2010 to 2020, with the most significant improvement in the upstream region and the most significant decline in the midstream region. The older adults’ health level in the YREB displays a gradient decreasing pattern of the downstream, midstream, and upstream regions. The health level of older adults in the YREB is influenced by a combination of natural and social environment factors. Areas with lower altitude and moderate humidity climates are more conducive to the health of older adults. The increase in influencing factors such as population migration rate, per capita GDP, average years of education, per capita housing construction area, per capita park green area, and green coverage rate in built-up areas is conducive to improving the health level of older adults, while lower number of health institutions per 1,000 people and higher household support rate are not conducive to improving the health level of older adults. In addition, over time, the health-promoting effect of natural environmental factors is enhanced from 2010 to 2020, and the influence of annual precipitation on shaping the spatial pattern of older adults’ health level became more obvious. Although the promoting effect of population migration on the health level of older adults tends to weaken, it remains the primary factor affecting the spatiotemporal differentiation of older adults’ health level in the YREB. The impact of social development on the health level of older adults has changed from a positive health effect (improvement) to a negative health effect (loss). The health-promoting effect of living environment factors is enhanced. The health-inhibitory effect of household support rate increased, and showed a gradient decreasing pattern from downstream to midstream to upstream. The findings of this study can provide a more in-depth understanding of the spatiotemporal pattern of the health level of older adults in the YREB and the factors influencing it, improve the health level of older adults in the region, and promote the development of healthy and active aging in the YREB, and improve the human health. At the same time, this study also supplements the related research on aging and the health level of the elderly. Firstly, it can provide reference for the research on the health of old adults in other countries and regions around the world. Secondly, it can also provide a basis for research on aging and the health of old adults in cities and counties under YREB.
