Abstract: Taking lightning disaster event occurred along the transmission line at the Yichang Prefecture of Hubei Province in 2013 as an example, in this paper we discuss the application of lighting nowcasting method to transmission line. Based on real-time high resolution radar data and monitoring data from lightning location instrument, we establish a lightning nowcasting model, by which lightning nowcasting within 30 min for a certain regions is made. Furthermore, we make early warning for lightning stroke along the transmission line by using a gridding method and calculating the distance between transmission line and lightning nowcasting region. Being simple and practical, this method is suitable to be used by the power department. Early warning results can be used as a reference in lightning risk assessment for transmission lines.