With the widespread application of video frequency technique and infrared imaging technique to power systems, the role of image information in the automation of power systems is becoming increasingly important, and higher and higher requirements for image processing and understanding are made. So in certain cases of application, monitoring people have to be replaced by the computer to understand images with the computer vision technique. This paper describes the basic contents of computer vision technique concerning its two aspects, i.e. image recognition and 3 D reconstruction. Based on some existing and assumed application examples, it investigates the necessity and prospects for application of computer vision technique (especially image recognition technique) to the automation of power systems.