Abstract: To prevent lump coal breaking and lower undersize fraction content,a series of effective measures,such as setting buffer platform,reducing height difference of loading point,putting in storage reasonable and laying buffer cushion etc,were taken based on the brittle and breakable coal,high height difference and big angle of loading point between the chutes in Yangchangwan second branch of Ningdong coal preparation plant. The results show that yield of lump coal is increased and undersize fraction content is reduced.