Abstract: It used the discrete element software to analyze mining rock stress and fissure which could simulate the changes response of continuous and discontinuous medium. The results showed that the mining stress change was related to the distance between mining face and the spacing of coal-rock seams in space; before complete mining, the stress change rule was symmetry "V" type - asymmetric "V" type - "W" type in near coal seams, and the stress change rule was symmetry "V" type - asymmetric type "V" type in far coal seams; the mining fissure showed the changes of mining stress, and the fissure development was related to the mining stress frequency of loading and unloading, the stress amplitude change was great, the fissure density was big and the last time was long for 15 to 30 m above the coal seam, which was the ideal position of gas drainage.