Abstract: Various types of coal mine monitoring systems require different functions of the substation. The hardware structure, data structure and communication protocols of various substations are not uniform, which leads to great difficulties in data fusion and sharing. In response to such problems, this paper designed a monitoring substation with general functions of distributed PLC. It can collect both switching and pulse data, as well as data from smart sensors via the RS485 interface. After combining, the data can be used by the monitoring substation for switching control. This design greatly reduces the types of substations in various monitoring systems, and achieves great convenience for data fusion and sharing and reduces the workload of system maintenance.