Combined with the difficulties in the actual use of building IoT, such as complex interface standards, difficult data sharing and low application efficiency of building IoT data, this article first summarizes the current situation of the use of Internet of things technology in building intelligent operation and maintenance. Combined with the requirements of building operation and maintenance management, the paper analyzes the application points of building IoT in building intelligent operation and maintenance, and discusses the application mode of building IoT in building intelligent operation and maintenance through IoT application project.