Abstract: In response to the complex transportation conditions of mine tunnels, long transportation distances of belt conveyors, and the high risk of runaway during transportation, this paper designs a damping idler for downward belt conveyors based on the main structure and specific working principle of the belt conveyor, in order to better ensure the safe and stable operation of downward belt conveyors in mines. The main structure of the damping idler is introduced, the key components of the damping idler are designed, and simulation applications as well as practical application tests are carried out to verify the effectiveness of the damping idler in controlling the operating speed of the belt conveyor. The research results indicate that the application of damping rollers can effectively control the operating speed of the conveyor belt, better ensuring the safe and efficient operation of the conveyor belt.