Under the urbanrural dual structure, the disparity in development between urban and rural regions has caused a significant overflow of rural residents, an aging rural population, and the phenomenon known as urbanrural inversion of population aging. The oneway crossregional movement of people has contributed to both the ruralurban population transfer and a significant regional age structure imbalance in China, which is a danger to the country’s longterm economic and social growth. Based on the panel data of 31 provinces from 2010 to 2019, we build fixedeffect and randomeffect models with the population aging coefficients as the explanatory variables to investigate the factors that influence population aging and the phenomenon of ruralurban inversion in urban and rural areas of China, as well as the performance of the three types of factors in the eastern, central, and western regions from three perspectives: demographic, economic, and social. The results show that demographic factors are the direct cause of urbanrural differences in aging, economic factors are the root cause, and social factors such as education, medical care, and social security have different effects between urban and rural areas and regions. As a result, the government should improve fertility assistance to raise fertility rates, promote integrated urbanrural development, stimulate the creation of eldercare services in rural regions, and promote regional connectivity and collaboration.