Abstract: Maluping mine is a high quality sources of raw materials which could produce highconcentration phosphate fertilizer directly without ore dressing, and it is rare in the world and the only one in China currently. Invein preparatory work mediumlength hole falling ore afterwards filling mining method was adopted. Through FLAC3D finite difference software, numerical calculation result such as characteristic of displacement and deformation, maximum principal stress of roof, roof vertical stress distribution, plastic zone distribution of stope of different mining spans of sublevel stope , reasonable stope span is 20m is obtained.

Key words: Maluping mine, Numerical calculation, Room span