Abstract: In view of problem of difficult location of fault existed in real time fault detection methods of powerful conveyor belt, the paper proposed an identification algorithm of joints of powerful conveyor belt based on image processing technology which takes a joint as a reference point. Firstly, based on the characteristics of joint points, a joint point is represented by a value. According to the value, upper or lower joint point could be distinguished simply. Then according to the features of joints, matching style of the longest common subsequence algorithm was modified and applied to recognize joint. The practical application showed that the algorithm has high precision and fast speed, can efficiently recognize joints of powerful conveyor belt and satisfy demand of joint locating of fault detection of powerful conveyor belt.