Aiming at the deficiency of traditional wildfire monitoring method. A system based on laser radar technology is proposed to monitor wildfire caused by the transmission line. The simulation experiment of laser radar system for monitoring the smoke was carried out at 560 m,460 m,360 m and 260 m from the distance monitoring point. The results verify that this system can accomplish wide range,high accuracy monitoring and evaluation of wildfire caused by the transmission line,which offer decision information for the safe operation and maintenance of transmission lines,and it can improve the reliability of the transmission network,and reduce wildfire accident rate caused by the transmission line.