The invention discloses a transmission line risk evaluation system. The system includes a collection module, an evaluation module, a storage module and a display module. The collection module collects transmission line operating data, tower specification parameters and meteorological real-time monitoring data. The evaluation module analyzes the collected data, carries out risk level evaluation on towers on transmission lines, and carries out risk state evaluation on sections on the transmission lines. The storage module stores the collected data and evaluation results. The display module displays the collected data and the evaluation results on a GIS platform. According to the system, processing and analysis results of the system are enabled to be highly accurate and applicable through connecting the transmission line data and the meteorological monitoring data in a butt-joint manner, data sharing is realized, and the platform is provided for transmission line display and an information concentration.