Abstract: The effect of karst-caves to blasting was analysed and the problem in perforation、charging、blasting,It indicated that karst-caves lead blast-energy leak out,change distance and direction from the blast center to the edge of sidestep,It would result in misfire through sympathetic detonation;perforate should keep away from karst-caves,take the way of suspensory detonator,Experiment shows that ignition in borehole sequence could reduce the effect of blasting root in karst-caves,improve blasting result,Especially it could avoid misfire,the level of safety in blasting should be enhanced.