Abstract: Based on geological survey at the scene and studies on rock mechanical properties of experimental samples，a analytical study is conducted using FLAC3D numerical simulation for the multilayer，multi-block and cross-stack complex goaf system of Weike Mine The calculating results show that the goaf system is in a stable state Then the numerical simulation study on the goaf processing plan proposed by the mine is carried out This analysis indicates that the treated goaf system is comparatively stable as a whole with partly cut through in structure，which does not achieve the desired effect of avalanche and penetrating the surface Based on stability analysis of goaf system，the improvement program to treat the goaf system is proposed Above all，considering various factors，the safe thickness of the goaf roof is comprehensively determined and the rocks at the top of security layer are stripped by blasting Then the reserved security layer of the roof at the top of the goaf is disposed with open deep hole compression blasting，thus an overlying rock protection layer of sublevel caving was formed by filling empty areas of breakout rock Finally the remaining rock system pillars are collapsed to achieve the treatment of the goaf.

Key words: Polylaminate goaf system, FLAC^3D, Stability, Blasting caving