Abstract: Abstract: During the conveying process of large sized coals in big drop chute in a coal preparation plant, several problems are existed such as the heavier impact of chute caused by large sized coals, the higher broken rate of large sized coals, and the higher noise and coal dust . The five structures of big drop chute under head funnel of belt conveyor, which each are size of cross-section, angle of inclination, part of triangle turning, flowing baseplate and tail end part, were optimized well. The new optimized structures of those will leave lump coals flowed easily in chute, and the amount of large sized coals broken resulting from collision decreased evidently.