With the economic development, the clean and low-carbon integrated energy system is of great significance to the social sustainable development in the world. Therefore, this paper proposes a novel energy supply efficiency evaluation model of integrated energy systems based on slacks-based measure data envelopment analysis (SBM-DEA) integrating Monte Carlo for energy saving and optimization. The extended energy supply data of integrated energy systems based on the Monte Carlo is verified in terms of F test. Then cooling load, heating load, electric load and internal combustion engine load are taken as inputs. And cooling income, heating income and electricity sales are set as desired outputs and the carbon tax is set as the undesired output to build the energy supply efficiency evaluation model of integrated energy systems using the SBM-DEA for energy optimization and carbon tax reduction. The results show that the proposed method has a high degree of discrimination to obtain better effective decision-making units (DMUs). Moreover, energy optimization and carbon tax reduction of integrated energy systems are achieved.