In order to realize autonomous wire-mounted UAV, a control algorithm based on visual servoing for wire-mounted UAV is proposed. The algorithm relies on the airborne binocular camera to realize the visual detection and location of the wire, according to the pre-calibration results of the ideal position and attitude of the wire, takes the slope and intercept difference of the wire as the main input of the control system, calculates the position and attitude control quantity of the UAV in real time, controls the UAV to approach the wire to be mounted, and makes the wire enter the mounting range of the airborne mounting mechanism. The test results show that the method can meet the accuracy requirements of the UAV wire within the allowable error range.