Abstract: To address the issue of insufficient discrimination in the optimization results and arbitrary determination of index weight in the integrated energy system operation plan, an evaluation method for integrated energy systems is proposed based on improved game theory combination and the weighted TOPSIS method. Firstly, a new game theory combination weighting model is established, aiming to handle the issues of large error encountered during combination weighting process. Secondly, the introduction of the virtual positive and negative ideal solution is beneficial to improving the TOPSIS method, thereby solving the problem of limited discrimination in traditional TOPSIS method. Finally, taking the integrated energy system data of a hotel in Shanghai as an example, the simulation results demonstrate that the proposed method reduces the error caused by the combination weighting process and enhances the distinction degree of the integrated energy system operation scheme as well.