Abstract: For mines that adopt stage open stoping with subsequent filling，reasonable selection of cement-tailing ratio and stope structure parameters plays a key role in realizing safe mining and improving production efficiency.According to the principle that peak deformation energy of backfill should be corresponded to releasing energy from excavated rock mass，the optimum backfill ratio of Zhongguan Iron Mine was determined to be 1∶6.Under this ratio，and based on the mine's mining condition，three-level and three-factor orthogonal experiment was designed to research how the room length，room width and top pillar height affecting stope stability.FLAC3D software was used to simulate the 9 different structure parameters，and the changes of stress and deformation of top pillar and backfill pillar after backfill were analyzed.The influence sequence of three factors in affecting stope stability was studied，and then the structure parameters were optimized.The calculation results showed that room length and width were important influence factors of stope stability，the optimal room length，room width，and top pillar height were determined as 50 m，18 m，8 m respectively.The mine could ensure stope stability and improve its production capacity effectively under these structure parameters.

Key words: Stage open stoping with subsequent filling, Strength match, Numerical simulation, Orthogonal experiment, Stope structure parameters