Based on the dynamic panel data for 31 provinces in China between 2000 and 2018, this paper examines the heterogeneous impacts of population ageing on technological innovation. We apply the system GMM method and reveal a humpshaped relationship between population ageing and innovation. Moreover, as compared with incremental innovation, population ageing poses a more noticeable negative impact on radical innovation at an earlier stage. We further employ the dynamic threshold regression to explore the nonlinear relationship between ageing and technological innovation. The results confirm the threshold effect of urbanization. In other words, once urbanization is below 86%, population ageing inhibits innovation.Otherwise, it could promote innovation. Therefore, the urbanization process could efficiently attenuate the discouraging effect of ageing on innovation.