Abstract: According to multi-system fusion requirements of monitoring system in Technology Schemes of Upgrading of Coal Mine Safety Monitoring and Control System, a coal mine fusion monitoring system based on Internet of things was designed, and solutions for underground data fusion and ground data fusion were put forward respectively. In underground data fusion, fusion substation provides comparatively independent data acquisition channel and service processing unit for each service subsystem in a region, and sends each kind of fusion data to corresponding service subsystem. Multi-service fusion gateway dispatches multi fusion substations to realize data fusion of across-region service subsystems. In ground data fusion, multi-system fusion software platform realizes sorted data storage, analysis, mining, comprehensive utilization and integrated display. Key technologies of coal mine fusion monitoring system were researched including main data, message service bus and "one map" model display. The system can provide unified and consistent data source support for intelligent mine, so as to realize integrated fusion and emergency linkage of monitoring systems.