To analyze the inherent laws of population aging level and health resource allocation in countries with moderate to severe aging, and provide reference for China's planning of health resources，this research collected 1824 panel data from 32 OECD countries from 1965 to 2021 to analyze the threshold effect of population aging on health resources. Results showed that: The level of population aging was significantly positively correlated with the proportion of health expenditure to GDP and the number of doctors per thousand population, with r values of 0.552 and 0.576, respectively, but negatively correlated with the number of hospital beds per thousand population (r=-0.146). There was a structural leap of 14.486% between the level of population aging and the proportion of health expenditure to GDP, with a correlation coefficient increasing from 0.1129 to 0.1691; At the level of 17.599%, there was a structural jump in the number of doctors per thousand population, with a correlation coefficient increasing from 0.0082 to 0.0259; There was no significant threshold effect between the level of population aging and the number of hospital beds per thousand population during the period of moderate to severe aging. It is recommended that China first enter areas with moderate to severe aging and increase efforts in training and investing in health human resources, while other regions plan ahead to actively respond to population aging.