Abstract: In order to overcome the shortcomings of the method currently applied in coal preparation plant for protection of longitudinal ripping of conveyor belt, it is proposed to use the machine vision monitoring mode, and an on-line monitoring software is developed based on the MATLAB image analysis function. The monitoring mode can be used in place of conventional belt ripping protection method featuring the use of proximity switch or observation with naked eye. Practice shows the machine vision monitoring mode can provide more accurate and timely belt ripping protection. Application of this mode is also the developing trend of intelligent coal preparation plant.