To ensure the effective stockpiling of tailings under the premise of safe mine production,a theoretical model,limit equilibrium method,Mathews stability diagram method,and numerical simulation technology were applied to analyze the stability of 2 stopes with large structural parameters:Shilingnan Shn-455 m and Shiling Sh-600 m in Fankou Lead-Zinc Mine.The analysis results show that the stope structure parameters designed based on mining requirements and engineering experience can keep the surrounding rock in a stable state,and the stability probability of the roof rock mass of Shn-455 m and Sh-600 m stopes is 89.8 % and 88.5 % respectively.Under the requirement of ensuring a 95 % stability rate of the rock mass,the allowable exposed roof strike lengths of Sh-600 m and Shn-455 m stopes are further determined as 53.6 m and 50.8 m.According to the numerical simulation analysis,the optimized stope structure parameters can ensure that the rock mass has a small settlement before and after the excavation.Meanwhile,the development of the plastic zone in the rock mass around the stope can be reduced by applying rock support measures,keeping a stable state of the stope with large structure parameters.This research result has important theoretical and practical guiding significance for ensuring the safe production of Fankou Lead-Zinc Mine,and can also provide a reference for the design and construction of similar projects.