In modern industrial production, belt conveyor is essential, its advantage is that it can save a lot of manpower and material resources. Belt conveyor accessories are more, the structure is complex, the complexity of the drum and the technical difficulty is higher. As we all know, the roller plays a great role in the belt conveyor, and its performance also determines the overall performance of the belt conveyor. There are many kinds of rollers on the market today. Because it carries a large number of different angles of force and friction, the loss is relatively large. In this paper, the drum structure is introduced first, and the expansion joint structure is selected as the research object. Then, the friction transmission principle between the drum and the belt is analyzed, and the variation of the envelope Angle and tension is calculated. Finally, the simulation results show that the acceleration of the improved drum is 0.1ms2 less than that before the improvement, indicating that the proposed research is helpful to the optimization of the belt conveyor drum.