For electric power visual technology in the construction process to ensure safe distance in the research, because the transmission line structure, special "sick area", using local information for three-dimensional matching speed is faster, but can not guarantee accuracy, especially the edge, occlusion, weak texture "sick area" has serious deficiencies, makes the transmission line identification and binocular vision three-dimensional matching task difficult. In order to ensure the accuracy of stereo matching and make more effective use of global information, this paper proposes a stereo matching algorithm of twin network combining segmentation results and fusion of geometric information, which can better stereo match such targets of transmission lines, and thus output depth images. In addition, there is a wide problem of empty pixels in the depth map. Introducing the depth smoothing function can better handle the position of the depth change in the depth map, and further improve the accuracy of three-dimensional matching. At the same time, the experimental results show that the depth map output of the proposed method is better accurate.