Background: As human beings enter the digital age, the impact of the digital economy on environmental regulation and corporate green technology innovation (CGTI) is expanding. In order to effectively strengthen the efficacy of environmental regulation and improve the green technology innovation ability of corporate, this paper conducts in-depth research on the influence process of the digital economy and environmental regulation on the CGTI. Methods: Based on the mediating variable environmental regulation, this paper explores the influence process of the digital economy on CGTI. Combined with empirical analysis methods such as the fixed-effect model, mediating effect model, spatial model and regression analysis, the authors reveal the influence process of the digital economy on CGTI. Results: The digital economy can directly promote the improvement of the green technology innovation level of CGTI. The digital economy can indirectly affect the CGTI through the mediating variable of environmental regulation, marginal effect and spatial spillover effect. Conclusions: The digital economy and CGTI had a significant spatial correlation among different regions in China. In different regions of China, there are significant differences in the relationship between the digital economy, environmental regulation and CGTI.

In recent years, countries around the world are significantly increasing their awareness of environmental protection. With a continuous expansion of economic scale, many emerging markets are also sustainably enhancing their standards for industrial carbon emissions in foreign direct investment (FDI). Therefore, the impact of FDI on the host country's industrial carbon emissions has always been a hot topic of researches by scholars. This paper selects panel data of 30 medium and large cities in China from 2006 to 2019, combined with dynamic panel GMM estimation and panel threshold model, and empirically analyzes the impact factors of FDI on the host country’s industrial carbon emissions from the perspective of dual environmental management systems. This paper draws the following conclusions: When taking the formal and informal environmental management system factors as threshold variables into the empirical research process, only the FDI in Beijing, Tianjin, and Shanghai shows a certain inhibitory effect on Chinese industrial carbon emissions. The FDI in other cities increases the scale of industrial carbon emissions. At the same time, in the formal environmental management system, FDI has no significant impact on Chinese industrial carbon emissions. It indicates that the formal environmental management system of each city is not effective in policy formulation or implementation, and it is not able to play the role of innovative compensation and forced emission reduction of the environmental management system. With the exception of Beijing and Shanghai, informal environmental management systems in other cities help curb the scale of industrial carbon emissions brought about by FDI.