While achieving economic growth, China's cities have also experienced severe environmental pollution problems. To achieve the goal of green production, this paper first measures the green total factor productivity (GTFP) of Chinese prefecture-level cities using the super Slacks-Based Measure and the global Malmquist-Luenberger index (SBM-GML) model and then explores the paths affecting GTFP from the perspective of information infrastructure construction policy (IICP) using a time-varying Difference-in-Difference (time-varying DID) model. The results show that the information infrastructure construction policy significantly contributes to urban GTFP growth overall, and the implementation of the policy leads to an average increase of 0.209 in pilot cities relative to non-pilot cities. The information infrastructure construction policy contributes to urban GTFP growth through green technology diffusion effects and the improvement of employment structure.