Abstract: In order to study the problem of transmission tower damage in the transmission tower-line system, this paper carries out the finite element modeling according to an actual transmission tower. Based on the analysis results, the damage state limit is determined and defined, and 20 ground motion records are selected for amplitude modulation. Using the incremental dynamic analysis method, the relative displacement angle between the rod nodes of the main material and the inclined material of the transmission tower is taken as the seismic demand parameter, and the peak acceleration of ground motion is taken as the intensity parameter, the fragility curve of the transmission tower is obtained by the IDA analysis method to analyze the seismic damage of the transmission tower. The fragility curve of the transmission tower in the system can be compared with the fragility curve of the single tower of the transmission tower, and the influence of the tower-line system coupling on the transmission tower can be obtained.