In recent years, the transmission line tripping accidents caused by lightning activity occur frequently.The corresponding research work is carried out aiming at the transmission line lightning protection technology. Based on the analysis of the lightning activity in Jiangsu, the tripping reasons and lightning characteristics are analyzed in many aspects including the style, height, circuit number and span of tower. The statistics of tripping times of Jiangsu power gird transmission lines from 2012 to 2016 are completed. Then, in combination with the actual production of power grid, the rationalization of lightning protection measures and suggestions are proposed from the aspects of transmission line differential evaluation, operation and maintenance and new technology.