In view of an investigation of the relationship between talent introduction policies and urban innovation performance, an empirical test has been made of the relationship by adopting a multi-period differences in differences method based on a panel data of 65 large and medium-sized cities in China from 2011 to 2019. Research has found that talent introduction policies have a significant effect on the improvement of urban innovation performance, while the intermediary effect analysis results indicate that talent introduction policies affect the innovation performance of cities with an optimization of their talent stock and structure. The results of a heterogeneity analysis show that the talent introduction policy has a stronger effect on innovation performance in first- and second-tier cities than in third- and fourth-tier cities; the improvement effect on innovation performance is stronger in eastern cities than in central and western cities, as well as in cities with better university resources than those with average university resources.