Abstract: In order to improve real-time performance and precision of detection method of conveying belt deviation, an automatic detection algorithm of conveying belt deviation was proposed combined with the advantages of OpenCV. Firstly, the algorithm uses CCD camera to capture video stream image of conveying belt real timely, and pre-processes the video stream image. Then it uses improved Canny edge detection algorithm to detect image edge. Finally, it adopts Hough linear transform to extract the belt deviation characteristics, and determine whether the belt is deviation or not, and make alarming if deviation. The test results show that the algorithm is simple and effective, has high speed of operation, and realizes automatic detection of conveying belt deviation.