Abstract: It is important to evaluate the performances of electric power construction enterprise scientifically, so an improved interval super efficiency DEA(SE DEA)model is proposed to solve this problem. The improved model has some advantages, such as overcoming the limit of using of certain value in normal SE DEA model, converting evaluation issues into SE DEA model with different weights according to different satisfactory levels of decision makers and determining efficiency value interval of Decision Making Unit(DMU)under different situation, and providing the information of sorting for the DMUs, etc. The proposed model makes good use of interval numbers and SE DEA method, which expands the application of classical DEA model, and provides a new method for the flexible management of the policymakers and regulators.