Abstract: The environment monitoring system for power transmission line based on laser and radar is composed by the spatial data management module, the inspection data processing module, and the landform change analysis module.It can collect the corridor space environment data, the safe distance of the earth and features, the terrain changes and the analysis and early warning of tower foundations lean highly and accurately.It's easy to shorten the inspection period, lower the cost, and improve the quality of inspection for Inner Mongolian 500 kV Xianggao line Ⅰ and Ⅱ through using the system.