Abstract: The preload,which is limited to Construction machinery and so on,can only reach 3 ~ 5t,deep soft rock roadway appears large deformation and requiresSeveral Repairs under low preload bolt support.This paper analyzes the failure phenomena and characteristics of the empty line roadway at four-level in Xing'an mine under the traditional bolt net support,reappears the whole process of roadway deformation and failureby FLAC^3D to draw up the failure mechanism of empty line roadway,namely:a lower preload support cannot restrict the deformation of surrounding rock and roadway is instability failure finally,proposes high preload bolt-net coupling support measures,which achieves good results after field application.