Abstract: Overhead transmission lines are the key to safe operation of power grid and reliable transmission of electric power, and it is very important to carry out regular inspection. The computer vision system has the characteristics of high integration, good interactivity, high degree of automation and fast processing speed, it can play an important role in the accurate identification and fault judgment of all kinds of equipment during the inspection process of overhead transmission lines, therefore, the computer vision system has a wide range of applications in the overhead transmission line robot inspection and fault diagnosis. In this paper, the robot computer vision inspection technology and its research status are summarized from the aspects of wire identification, tower identification and insulator string identification, the corresponding image processing methods are analyzed, on this basis, the overhead transmission line robot visual inspection key technology has been summarized and foreseen.