In order to examine the impact of population age structure changes on innovation, this study utilizes microlevel data from the 1990 and 2000 national censuses, the Chinese Patent Database, the CSMAR Database, as well as data from the Urban Statistical Yearbook. A population structure change index is constructed using the proportion of young labor force predicted based on historical birth years. The study investigates the effects of population age structure changes, particularly the changes in the proportion of the 20-34 age group relative to the labor force, on regional innovation performance. The findings demonstrate that an increase in the proportion of young labor force has a significant promoting effect on both the quantity and quality of patents. The impact of age structure changes on innovation in non-state-owned enterprises is more pronounced compared to state-owned enterprises, and it is more likely that young labor force promotes innovation through the labor supply channel.