Integrated energy system is an important direction of change in the field of energy. It can improve the efficiency of energy use, reduce environmental pollution, and meet the diverse needs of users. A scientific and reasonable evaluation of these projects is an important means for the horizontal comparison and analysis of different projects and technical schemes, as well as an important prerequisite for the large-scale promotion of integrated energy demonstration projects. The optimal and worst method is used to determine the subjective weights of indicators, the variance coefficient method is used to determine the objective weights, and then the objective and subjective weights are organically combined based on the weighting deviation vector minimum combination weighting model. Subsequently, this paper evaluates the integrated energy demonstration project using the improved combination weighting evaluation method to verify the rationality and feasibility of the proposed method.