New industrial land use policy and firms’ green technology innovation in China—an empirical study based on double machine learning model

China is facing a serious land resource mismatch problem, which will profoundly affect the acceleration of economic growth and technological innovation. Reform of the industrial land allocation system can solve the mismatch of land resources, and that also has an important impact on the promotion of economic and technological development. This paper selects the data of Chinese A-share listed companies in Shanghai and Shenzhen from 2007 to 2020 as the research sample, constructs a double machine learning model, and empirically investigates the impact of a new industrial land use policy on firms’ green innovation behavior. The study shows that: (1) the new industrial land use policy significantly promotes firms’ substantive and strategic green technological innovation, and the effect on substantive green technological innovation is greater than that on strategic green technological innovation. (2) The enhancement of R&D investment sustainability and the “talent pool” effect are important mechanisms through which the new industrial land use policy influences firms’ substantive and strategic green technological innovation. Meanwhile, the new industrial land use policy is conducive to firms’ green co-innovation. (3) There is heterogeneity in the effect of the new industrial land use policy, which can significantly promote green technological innovation of firms in the eastern region, while it does not play a significant role in the green innovation behavior of firms in the central and western regions. The above research results enrich the research in the field of industrial land and innovation, help to understand more comprehensively the mechanism of new industrial land affecting firms’ green technological innovation, and provide policy insights for strengthening the application of industrial land allocation reform in firms’ green innovation.