This paper proposes an interval optimization model for the integrated energy system considering the uncertainty. First, the source-load uncertainty is modeled in the form of intervals. Then, a model of the integrated energy system in the community with electricity/ heat/ cooling/ natural gas/ hydrogen is developed. Finally, an interval optimization dispatching model considering the economy is developed. The case study discusses the impact of source and load uncertainty on the integrated energy system dispatch. As the range of source load fluctuation increases, source load uncertainty's impact can be mitigated by improving short-term prediction accuracy. And according to the results of the cases, the method of smoothing the uncertainty is discussed. When the source-side uncertainty increases, the system smoothens the fluctuation by increasing or decreasing the power purchase. When the load-side uncertainty increases, the impact on the integrated energy system involves all the energy networks, and the system will change the operation state dramatically to smoothen the fluctuation.