Abstract: The paper introduced X-ray detection theory, designd a monitoring system of conveyor belt of steel rope core based on X-ray, and expounded design of hardware and software in details. The system can realize on-line and full speed detection and provide X-ray transmission image at any location of the conveyor belt. Through comparison and processing of image of the conveyor belt, the system can locate the areas of wire damage, wire stretching and patch spot, and give an alarm automatically.