Abstract: In view of problems of leak-detection and misinformation existed in present detection methods of belt connector state, an image acquisition system of underground belt connector was designed. The system adopts inductance-type proximity switch to detect belt metal connector real-timely and also controls digital camera to capture the images of the positions of travelling belt automatically. Then, it uses underground looped network to transfer the images to the ground monitoring room , so as to achieve real-time capturing and processing of the belt connector images and eliminate hidden danger of tearing, tripping of the belt connector in time.