Computer Generation Image (CGI) system is main part of the flight simulator. Usually, the Image Generation Workstation to be used in CGI system is very expensive. This paper presents a low cost CGI system based on PC and we use it to develop a flight simulator, which has a 3 channels display system with wide field-of-view (horizontal 240°× vertical 60°). First, the paper discusses the architectural principles of CGI system and provides a CGI system based on PC. Second, a type of 3 channels display system is described. The display system is designed in folded flat screen using rear project curtain. Adjacent screen shapes a 100° corner and each channel provides 80°×60° field-of-view. Furthermore, some key technologies, such as image connection, channels synchronization and channels communication, are discussed in detail. At the end of paper, a flight simulator with 3 channels visual scene is described and it is successfully implemented in training pilot. PC-Based CGI system also can be applied to a lot of fields including multimedia commerce, medical media databases visualization, CAD/CAM, scientific computing visualization, and entertainment.