In view of the problems in the operation of the substation monitoring system of Cilinshan Coal Industry, the design study of the substation monitoring system was carried out by using the microcontroller control technology, and the field application test was conducted. The practice showed that after using the monitoring system, the troubleshooting time of substation was shortened by 50%, and the uptime was increased by 45%. The monitoring system had perfect functions, stable and reliable performance, which is important to improve the operational safety of substation, and provided a reference for the upgrade study of substation monitoring system in the later stage.