Abstract: The operation times of arrester counter is one of the main indexes for judging the operation status of ar-rester． It is very difficult to calculate the operation times of arrester through the artificial and unmanned aerial pho-tographs． So a new method was proposed to calculate the number of actions of arrester with fixed clearance based on the data of lightning location system，transmission line equipment account and lightning protection mechanism．The effectiveness of the method was verified by a practical example． Firstly，lightning-induced area of the line was determined by the parameters of transmission line and lightning current，and all lightning currents in lightning-in-duced area were calculated according to the installation time of lightning arresters and the data of lightning positio-ning system over the years． Then，the lightning resistance level of the line was calculated with method of regula-tions，and the maximum and minimum lightning current value and lightning shielding rate of the line were calculat-ed based on the improved electrical geometric model． Finally，the operation times of arrester with fixed clearance was calculated by analyzing the number of flashover caused by counterattack lightning and encircling lightning． The
case study shows that the operation times calculated by this new method are basically consistent with the actual op-eration times，and it can effectively calculate the probability of action times of arrester caused by counterattack lightning and encircling lightning．

Key words: transmission line, lightning arrester with fixed clearance, lightning current parameter, improved e-lectrical geometry model, ightning-induced area, operation times