Due to the serious air pollution, the renewable energy sources had attracted more and more attention. In order to manage the renewable energy sources, the concept of microgrid is introduced. The IoT system can also be used in microgrid for the monitoring and control. However, how to verify the reliability of the system is still a problem. In this paper, the probabilistic model checking is used to verify the reliability of IoT system in microgrid. The results suggest the further improvement of IoT system in microgrid.