In view of the problems existing in the current cable winding machine, such as the untimely return to the edge, low efficiency and reliance on manual reverse, a line laser sensor is used to detect the real-time dynamic situation of the cable arriving to the edge of the cable winding machine, and the lateral movement direction of the winding machine is adjusted timely according to the results. Firstly, according to the cable and the special position of the baffle node, the segmentation of point cloud data was achieved via concave and convex constrained point detection algorithm. Secondly, using RANSAC algorithm of baffle linear fitting, the data after using slope characteristics were found in cable data cable under test, with measuring cable the overall least square circle. Finally, the relative position of the cable was calculated to the damper under test. Experimental results show that the algorithm can accurately find the data segmentation point and calculate the distance between the cable to be tested and the baffle, which realizes the real-time detection of the reverse to the edge during the winding process of the cable.