Abstract: As one of the main transportation equipment in coal mines, the automation level of belt conveyors determines the efficiency of coal transportation. Due to the complex operating conditions and heavy load of long-distance belt conveyors in coal mines, the conveyor belt undergoes significant elastic deformation. Therefore, a tensioning device needs to be used to give the conveyor belt a certain amount of tension to ensure normal use. Based on the working characteristics of the belt conveyor, a tension control device is constructed by combining frequency conversion control and torque control. This device uses a tension sensor to monitor the actual tension of the conveyor belt in real-time, and PLC and frequency converter analyze the tension and control the motor operation to achieve tension adjustment. The constructed tension control device has a simple structure and is easy to maintain. After on-site application, it can meet the tension control needs of belt conveyors and improve the reliability of equipment operation.