Abstract: The boulder,rock wall.bottom toe always appear in limestone mine mid deep bench blasting because of bedding,fault,joint and cave.Through the analysis of the geological structure characteristic and the reason of producing boulder,rock wall and bottom toe,the blasting test research has been made.According to the research results the suitable technical measures have been adopted,the better blasting effect has been obtained,and also through renewing the drilling equipment,adopting middle pressure airmover,the driling efficiency has been increased,the resources consumption can be decreased This experience can be a reference for similar mines. \ \