Abstract: In response to the dust problem caused by material dropping at the transfer point of belt conveyors, a graded material dropping dust reduction device is designed. The first stage material dropping dust reduction device, the second stage material dropping dust reduction device, and their connecting structures are optimized through numerical simulation. The results showed that after optimization, the outer cylinder diameter of the first stage device was 2550 mm, the diameter ratio was 0.45, and the insertion depth of the inner cylinder was 600 mm. The dust suppression rate for dust larger than 5 μm reached 69.64%; Under parameters such as a secondary device dust outlet diameter of 109.1 mm, the dust suppression rate for dust larger than 2.5 μm is 58.21%; When the angle between the connecting structures is 90°, the total dust suppression rate of the device is 97.76%, and the simulation and experimental trends are in good agreement, providing technical support for dust control in coal preparation plants.