Abstract: By analyzing the influencing factors for isolated pillars in recovery process，and combining with practical engineering，six influencing factors for the isolated pillar and room including stope sidewall height(A)，sidewall thickness(B)，stope length (C), stope width (D), whether alternating backfill after mining(E), whether the full tailings cementing backfill at second step(F).Two levels are selected for each factor.8 simulation experimental programs were identified by analyzing the selected orthogonal table L₈（2⁷）.The isolated pillar model was established，and the stress distribution of the isolated pillar before excavation was analyzed by refutation.The excavation with orthogonal scheme was simulated based on FLAC3D numerical simulation software.The simulation of stress distribution and displacement after the isolated pillar was mined. The analysis results show: the displacement ranges of 6 influence factors A,B,C,D,E,and F in Y direction are respectively 4.8,0.698,1.404,1.305,1.623 and 0.164 mm.That is to say,the stope sidewall height (A) of isolated pillar has the most significant impact on its stability，and whether adopting the full tailings cementing backfill at second step (F) has a minimal impact.

Key words: Isolated pillar, Stability analysis, Orthogonal test, Influencing factors