In order to effectively evaluate ethylene industry’s energy efficiency level

and search for an opportunity to improve the energy efficiency

an ethylene industry’s energy efficiency evaluation method based on energy performance index(EPI)is proposed in this paper

which is according to data’s characteristic of the ethylene industry

and considers the activity effect

structure effect

intensity effect of energy consumption.Then the EPI and ethylene yield with data envelopment analysis(DEA)are analyzed.Finally

an example based on the energy data of several ethylene plants is presented.The results verify the accuracy and validity of the method and provide a new way to evaluate the efficiency of ethylene plants.