Abstract: Rational stope structural parameters may lead to a favorable mechanic state for the stopes and the stress and strain distribution of the wall rocks may become more homogenized.Under this condition，support workload is reduced and the mining intensity as well as the production efficiency can be improved on the premise of ensuring the stable exploring system and safe production.Based on the geological situation and mining methods of Sishanling iron ore，two-level orthogonal experimental design is made to decide the key five factors affecting the room exploring stability，i.e.room height，room width，stope length，pillar width and pillar filling method.Then，eight experimental schemes are concluded.The finite-difference software FLAC^3D is adopted to make numerical simulation on the stope structural parameters of different scheme at panel，and to obtain the feature of the stress，displacement，and plastic zone under different structural parameters.It is preliminarily obtained that the optimal structure parameters which can stabilize the stope is the height of stope 60 m，the length of stope 60 m，the width of room 18m，and the width of pillar 20 m.The calculating results show that the stope length of the roof influences the stress and roof displacement maximum，i.e.the longer the stope，the greater the stress.The compressive stress mainly concentrates on the panel pillars，while the tensile stress concentrates on the roof and the bottom.The results may provide technical support for safe and efficient mining of rooms and pillars within panel．

Key words: Orthogonal experimental design, Deep &, large-sized orebody, Stage room mining method with subsequent filling, Optimization of Structural Parameters, Numerical simulation