As a typical intelligent energy system, integrated energy system can promote the integration of sources, networks and loads, and improve the utilization of renewable energy. Therefore, intelligent energy systems should be evaluated in terms of core features as low-carbon and high-efficiency at the same time. Based on the concept of multi-energy complement, a new evaluation index, the comprehensive energy efficiency level, is proposed to describe the energy utilization efficiency of multi-energy systems. Considering that the economy of energy consumption is the core driving force of the user to spontaneously adjust the strategy of energy use, this paper takes the maximizing comprehensive energy efficiency level and improving economy of energy consumption as the optimization objective, proposes the multi-objective optimization model of the integrated energy system, and obtains the optimal strategies of energy use under the restrains of both physical and cold-heat-electricity balance, and realizes the optimal dispatching of the system. A case analysis shows that the proposed optimal dispatching strategy can improve the clean-liness and efficiency of the system.