Abstract: With the advancement of deep mineral resource development，the ultra-deep shaft of San⁃ shandao Gold Mine faces engineering challenges of poor surrounding rock stability and difficult support due to high ground stress，complex joint development，and groundwater effects.This study integrates rock mass quality classification，mechanical parameter analysis，support design，and numerical simulation to construct a technical system for surrounding rock stability control suitable for this engineering context.The Q-system，RMR，and GSI methods were used to assess the rock mass quality at different depths of the shaft，identifying the distribution characteristics of higher-quality shallow surrounding rock，reduced deep quality，and significant integrity differences.Combined with laboratory rock mechanics tests and the Hoek Brown strength criterion，the heterogeneity law of rock mass mechanical parameters varying with depth was revealed.Based on the classification results and engineering analogy，a composite support scheme dominat⁃ ed by shotcrete with wire mesh and bolts，supplemented by cable bolts was determined.Parameters such as bolt length，spacing，and shotcrete thickness were optimized through empirical formulas and theoretical calculations，and a support structure of "energy-dissipating bolts +shotcrete with wire mesh and cable bolts +lining"was designed for deep areas.Phase2 simulations of different support conditions showed that the composite support of "shotcrete with wire mesh and cable bolts +lining"can effectively control sur ⁃ rounding rock deformation，reduce the plastic zone range，and optimize stress distribution.Compared with the unsupported state，the maximum surrounding rock displacement and plastic zone range were reduced by 42%and 68%，respectively，with significantly alleviated stress concentration.The research results pro⁃ vide an integrated solution of "grading evaluation-parameter optimization-composite support"for the ultra deep shaft of Sanshandao Gold Mine，which can offer reference value for surrounding rock stability control in similar deep mine shaft projects.

Key words: ultra-deep shaft, surrounding rock stability, support design, numerical simulation