Based on the era of dividends brought about by the construction of information infrastructure, it is of great significance to explore the impact of it on digital-intellectual innovations such as digitalization, cloud computing, and artificial intelligence. The driving path were discussed. Utilizing data from 284 Chinese cities from 2011 to 2021, an empirical model of information infrastructure construction on digital-intellectual innovation was constructed. It finds that the construction of information infrastructure, represented by the “Broadband China” strategy, effectively enhances the level of technological innovation in digital-intellectual innovation, such as digital technology, 5G technology, artificial intelligence technology, information technology and e-commerce technology. The conclusion remains valid after various robustness tests. Mechanism tests show that information infrastructure construction enhances digital-intellectual innovation by increasing the concentration of digital-intellectual talent and optimizing the digital-intellectual industrial environment. Heterogeneity results show that the positive impact of information infrastructure construction on digital-intellectual innovation exhibits a clear gradient effect across different regions, progressively strengthening from the central-western to the eastern regions, and from cities without high-speed rail to those with high-speed rail. It provides a theoretical base for optimizing the spatial layout of information infrastructure construction and enhancing the capacity of digital-intellectual innovation.