Abstract: Using the provincial panel data of 30 provinces and cities from 2007 to 2018, the effect path of power consumption level on eco-efficiency was analyzed through the mediating effect method and threshold effect. Then, a panel threshold regression model is constructed to analyze the regional heterogeneity of the effect of power consumption level on eco-efficiency when power consumption level, per capita economic development level and foreign investment are threshold variables. The research results show that: the power consumption level not only has a direct effect on eco-efficiency, but also indirectly affects ecological efficiency through the path of technical innovation. There is regional heterogeneity in the effect of electricity consumption level on eco-efficiency. With the gradual increase of electricity consumption level, the impact of electricity consumption on eco- efficiency changes from a significant negative effect to an insignificant one, and finally even it evolves into a positive effect at a significant level of 1%; when the economic development level of each region is used as the threshold variable, the negative effect of electricity consumption level on eco-efficiency is inverted "U"; when FDI is the threshold variable, the negative impact of electricity consumption level on ecological efficiency shows a declining trend.