The invention relates to an automatic insulator maintenance method for use in a power transmission and distribution system. The method utilizes a robot to do the maintenance work, and the robot comprises two sets of fixed parts, two sets of adjusting parts, two sets of right angled parts, a telescopic part, a positioning part, a hydraulic power part, a monitoring part, a controlling part and a machine carrying part. The two sets of fixed parts, two sets of adjusting parts, and two sets of right angled parts are connected to the front end and the back end of the telescopic part. The fixed parts are connected to the adjusting parts and rotate to the right angled parts through the adjusting parts. The right angled parts are connected to the telescopic part; the top of the telescopic part is fixedly provided with the positioning part. The monitoring part is fixedly arranged at the side part of the fixed parts. The controlling part controls the movements and the gestures of the robot and communicates with an unmanned machine; the machine carrying part is fixedly arranged at the lower end of the unmanned machine. According to the invention, automatic operations can be realized to increase performance efficiency.