A simplified single tower model of the transmission tower line system was established by si-mulating the quality of the transmission line using quality units and simulating the equivalent stiffness of the transmission line inside and outside the plane using spring units as boundary conditions. Taking a self-standing steel tube transmission tower in Laoting County, Tangshan City, Hebei Province as the engineering background, the single tower simplified model was established and the traditional three tower two line model was used to calculate the wind-induced dynamic response of the structure. By comparing the wind-induced dynamic response of the two models under different wind direction angles, initial horizontal tension of transmission lines, and different transmission line spans, the applicability of the single tower simplified model was studied. The results show that under wind direction angles of 0°, 45°, and 90°, keeping the span of the transmission line unchanged, when the initial horizontal tension at both ends of the transmission line increases by 20% and decreases by 20% respectively based on the refe-rence value, the root mean square of displacement response and the root mean square of maximum main material stress obtained by the two calculation models at different heights are basically consistent, and both show a pattern of increasing deviation with the increase of transmission tower height; The deviation of structural dynamic response obtained by the two calculation models increases with the increase of transmission line span under different transmission line spans. Among them, the root mean square devia-tion of displacement response is more significantly affected by span than the root mean square deviation of main material stress. Therefore, the simplified tower model proposed is suitable for wind-induced dynamic response calculation of transmission tower line systems with spans less than 700 meters. In addition, in transmission tower line systems with smaller tower heights, the simplified model of the bill of lading tower has higher computational accuracy.