The pipe inspection robot system is developed for automatic inspection of gas pipeline with pipe diameter between 400 mm and 650 mm. It is composed of a pipe robot crawling mechanism controlled by remote network system, nondestructive examination sensor system, ground working station and so on. This paper presents the pipe inspection robot system design, the Key technique and the performance experiment of the robot. The main performance index of the pipe robot system prototype has reached domestic advanced level. The prototype has also the technical potential to be developed as a product used in industry for periodic check of main gas/oil pipe. The pipe inspection robot system is developed for automatic inspection of gas pipeline with pipe diameter between 400 mm and 650 mm. It is composed of a pipe robot crawling mechanism controlled by remote network system, nondestructive examination sensor system, ground working station and so on. This paper presents the pipe inspection robot system design, the Key technique and the performance experiment of the robot. The main performance index of the pipe robot system prototype has reached domestic advanced level. The prototype has also the technical potential to be developed as a product used in industry for periodic check of main gas / oil pipe.