The Impact of Digital Economy and Environmental Regulation on China’s Regional Total Factor Energy Efficiency

Against the backdrop of the “dual carbon” goals, improving total factor energy efficiency (TFEE) has become a core task for low-carbon transformation. Using a panel dataset covering 30 provinces in China from 2011 to 2024, this paper employs the super-efficiency SBM model to measure regional TFEE, and applies the spatial Durbin model and threshold regression model to examine the impact of the digital economy, environmental regulation, and their interaction on TFEE. Different from traditional linear analysis, this study reveals the nonlinear mechanism through which the digital economy unlocks the potential of environmental regulation and transforms its effect from “compliance cost pressure” to “innovation compensation gain”. The findings show that: First, the digital economy significantly promotes TFEE, with 56.68% of its energy-saving effect realized through spatial spillover. Second, environmental regulation alone shows a “cost-following effect” and inhibits TFEE, but its interaction with the digital economy generates a strong synergistic effect with a coefficient of 0.299. Third, the digital economy acts as a critical threshold: only when its level exceeds 0.435 can environmental regulation effectively boost TFEE via the innovation compensation effect. Fourth, the synergistic effect has strong spatial spillovers, with the indirect effect (0.383) exceeding the direct effect (0.282). This study contributes new evidence that digital infrastructure construction should be prioritized in regions with strict environmental regulation to avoid efficiency losses, and provides targeted implications for implementing regionally differentiated policies that prioritize digital upgrading to match environmental regulation intensity to coordinate digital development, environmental governance, and energy efficiency improvement.