This study examines the impact of such policies on energy efficiency by focusing on the “National Comprehensive Demonstration of Energy Saving and Emission Reduction Fiscal Policy” (ESER fiscal policy). Using a difference-in-difference method with multiple time points, the study finds that the ESER fiscal policy has significantly closed total factor energy efficiency (TFEE) gap. The results are robust, supported by sensitivity analyses such as variable substitutions, dynamic effect tests, exclusion of potential intervening variables, placebo tests, and propensity score matching. Mechanism analysis reveals that the pilot program closes energy efficiency gap through increased expenditure on environmental protection, improved agglomeration of productive services, and promotion of green technological innovation. Furthermore, the impact of green fiscal policies on TFEE is more pronounced in cities within two-control areas, non-old industrial base cities, large-scale cities, and resource-depleted cities. The analysis of the energy rebound effect found that green fiscal policies can effectively close the energy efficiency gap without generating energy rebound. These findings offer valuable insights and empirical evidence for the effectiveness of China's green fiscal policies in driving green development, improving quality, and enhancing efficiency.