The overhead transmission line has the characteristics of large span, soft quality and low damping, it is very sensitive to the action of wind load. The buffeting tensions at the junction of the conductor and its end under the action of the fluctuating wind are the most difficult points in the structural design of the transmission line. Based on the theory of random vibration of structure and the mechanics of cable structure, the dynamic response in static equilibrium state is divided into background response and resonant response. The background component determined by using the effect string function is discussed emphatically. The frequency domain analytical solution of the background response power spectrum function and the root mean square of the along-wind dynamic tension (perpendicular to the plane direction of the conductor) are given. The wind tunnel test of full aeroelastic model of two-span 4-bundle conductor is designed and completed. Considering the three connection modes of tensile insulator, I insulator and V insulator. The action law of dynamic tension in wind-induced space is investigated by using high frequency force balance device. The study shows that the influence of different types of insulators on the along-wind tension response is obvious. The nonnegligible aerodynamic damping effect makes the background response account for most of the total dynamic response. At the same time, the relative accuracy of the theoretical model is verified by wind tunnel test.