We constructed an internet development index and used inter-provincial panel data from China between 2006 and 2016 to empirically test the impact and the mechanism by which internet influenced green productivity. Internet strongly promoted green productivity growth in China, and its influence showed clear regional heterogeneity, with positive effects in the eastern and central regions but no effect in the western region. Internet not only promoted green productivity directly, but also had an indirect positive effect on green productivity by accelerating technological innovation and industrial structure upgrades. Nonetheless, its direct effects far exceeded its indirect effects. More importantly, we found that the positive effect of internet on China’s green productivity showed significant non-linear characteristics. When the development level of internet crossed a critical threshold, its influence was significantly enhanced. At the same time, R&D investment and industrial structure upgrading can further strengthen the network effect of internet. These findings provide important theoretical guidance for the application of internet and associated strategies to promote green economic growth in China.