In recent years, with the rapid development of power grids, more and more cables have been applied to urban power grids. With the increasing size of cable lines, a serious problem has become increasingly obvious — cable line faults. The fireproof, gasproof, explosion-proof, waterproof and anti-theft issues of cable tunnels are becoming more and more important. To meet the requirements of the “five preventions” of cable tunnels, the operating environment of the cable must be monitored to find problems early and deal with them in time to avoid major problems. . In order to meet the requirements of intelligent, informatized, and automated smart grid construction, the entire high-voltage cable online monitoring system uses a high-speed, strong, and reliable optical fiber network as the information transmission medium, uses Ethernet technology to transmit monitoring data, and uses ring network technology to ensure The data is stable and reliable. HANSUN uses HX2016W-8SFP, HX2004-2SFP, HX2005, HX2008 industrial switches in the high-voltage cable solution of the transmission grid, and uses an Ethernet switch at each monitoring point of the entire system to pass various monitoring signals of the monitoring points through the optical fiber ring network Converge to the central monitoring station.