Abstract: large number of goafs existed in Hongling PbZn Mine,in order to guarantee the safety mining of the mine,based on FLAC3D numerical simulation software,the stability of chambers during the stoping process and distribution characteristics of insitu stress are studied in depth.Combing with the field investigation results,indoor rock mechanical test results,the numerical model is established by using FLAC3D software,so as to evaluate the stoping stability of the chambers in four middle sections,and the analyze the influence regularities of chamber stoping to the stability of its upper or lower surrounding rock and the distribution characteristics of plastic zones.The study results show that:①chamber span,exposed area of goaf and the size difference of adjacent column are the important factors that affects the chamber risk assessment;②with the increasing of mining depth,the tensile stress and compressive stress of the roof and floor of the middle sections are appeared obviously,the tensile stress range of the upper surrounding rock of goaf is more greater;③the 3109 chamber of three middle section and 4102,4105 and 4108 chamber are belongs to the dangerous ones,it is necessary to take some relative supporting measures.

Key words: Chamber stoping, Stability analysisInsitu stress, Numerical simulation