Abstract: Digitization and intelligence are important supports for the high-quality development of the power grid, and the transmission line monitoring system is one of the main application forms of the power grid digital transformation. This paper introduces the background of digital operation and maintenance transformation, and summarizes the construction significance of online monitoring systems based on the physical characteristics of transmission lines. The overall architecture, hardware configuration and key technologies of the transmission line monitoring system based on edge computing, as well as the panoramic monitoring business process based on the system, are described in detail. Finally, taking a power supply enterprise as an example, combined with typical application examples, the application effect and shortcomings of the system are analyzed, and the future development trend is prospected.