Abstract: After years of mining，there exists a large number of underground goafs in Sandaozhuang Mine. These underground goafs scatter widely with the complex form，and have become the main potential safety problem of mining production. On the basis of analyzing the geology of the northern burst area around 1330m terrace，the distribution features of underground goaf areas can be got through drilling in the blasting area. Based on the real bench situations，the medium-deep hole blasting in the usual bench is simultaneously carried out with treatment of underground goafs in the blast area，which integrates the blasting work and the goafs treatment. A good blasting effect was obtained with micro differential hole-by-hole blasting network. This method can ensure the production work in the bench and get rid of potential goaf safety problems at the same time.

Key words: Medium and deep hole blasting, Underground goaf, Open-pit working, Blasting network, Evaluation