Using the panel data of each province in my country from 2011 to 2020, considering the radial and non-radial characteristics of different input and output indicators, as well as the inseparability between energy input and undesirable output, a hybrid data envelopment analysis（DEA） model with the inseparability of undesirable output is constructed to measure the total factor energy efficiency of each province in my country, and further calculate the energy saving and emission reduction potential. It is found that, the overall total factor energy efficiency average from 2011 to 2020 is 0.725.There are large differences in total factor energy efficiency among provinces. The provinces with the highest energy efficiency are concentrated in economically developed provinces such as Guangdong, Beijing, Jiangsu, and Shanghai. The provinces with the lowest energy efficiency are Inner Mongolia, Shanxi, Xinjiang and Hebei. From a national perspective, the energy saving potential is 40.7%, which is far less than the emission reduction potential of various pollutants. The gap between energy saving potential and emission reduction potential varies in different provinces. It can be roughly divided into two categories: the type represented by Liaoning that promotes both energy conservation and emission reduction, and the type represented by Jiangsu that prioritizes emission reduction over energy conservation. The research results can provide certain scientific reference for the formulation of regional energy conservation and emission reduction policies in my country.