Abstract: In the second-step stoping of stage open stoping with subsequent filling method，the blasting damage to the filling body，resulting in a large number of filling body collapse，affecting the stabil⁃ ity of the filling body and stope mining safety. In order to effectively control the destruction of filling body caused by blasting operation，based on the engineering characteristics of Zhangzhuang Iron Mine，through theoretical analysis，the thickness of wall protection pillar of high-stage second-step stoping room and the blasting parameters of high-stage side wall are obtained. The boundary blasting effect is analyzed through industrial tests and three-dimensional scanning of the goaf. The results show that this high-stage secondstep stoping buffer blasting scheme has formed a good blasting effect，which has reference value for the same type of mines.

Key words: second-step stoping, wall protection pillar, buffer blasting