Abstract: Aiming at the problems of poor reliability, difficult common fault location for the existing monitoring system of belt conveyor in coal mine, a monitoring system of belt conveyor with fault location function based on RS485 and CAN bus was designed. According to the site operation situation, the monitoring quantities and the control quantities of the system were determined, the overall design scheme of the system was completed, the emergency stop module, the amplify telephone，the lower computer and the terminal module was designed, the fault comprehensive judgment procedure was compiled, and a common fault location method based on RS485 and CAN bus was presented. The test results show that the system has the characteristics of complete monitoring, accurate location and reliable communication, which can meet the needs of coal mine production.