Abstract: The safe and stable operation of transmission lines is an important guarantee for power supply safety.In order to reduce transmission line accidents caused by external force damage or device defects, State Grid Beijing electric power company has researched and built an intelligent security system for transmission lines based on video acquisition and intelligent identification of hidden dangers.The image acquisition terminal, model algorithm and control mode are continuously optimized, and the image acquisition efficiency, algorithm recognition performance and operating capabilities are gradually improved.The whole process of transmission patrol inspection based on intelligent system is realized, and the efficiency and quality of transmission line inspection are effectively improved.