Based on the panel data of provinces and cities from 2007 to 2019,the entropy method was applied to measure the level of financial eco-environment,and the two-way fixed effect model,threshold regression model and bias-corrected nonparametric percentile Bootstrap were used to empirically analyze the effect and mechanism of financial eco-environment on carbon emission reduction.The study shows that the improvement of financial eco-environment has carbon emission reduction effect,and the financial eco-environment reduces carbon emission intensity by promoting technological innovation and optimizing energy consumption structure.Further research finds that the carbon emission reduction effect of financial eco-environment has a threshold effect and regional heterogeneity.With the improvement of financial eco-environment,the carbon emission reduction effect is enhanced.The carbon emission reduction effect of financial eco-environment in the central region is stronger than that in the eastern region,and the emission reduction effect is not significant in the western region.In view of this,targeted improvement of the financial eco-environment level in various regions not only has a positive promoting effect on economic development,but also benefits the achievement of China's"dual carbon"goals.