Abstract: By using FLAC2D, the influence of different drilling diameter, drilling distance and burial depth to drillhole pressure relief has been simulated in this paper. It can be proved that : (1)After the drillhole was implemented, the stress concentrated in the left and right sides, either the stress pressure was relieved around especially both sides of the up and down of the drillhole.Meanwhile,the greater the diameter of drillhole, the better the effect of the drillhole pressure relief, the destruction of coal around the drillhole is becoming more and more serious. The distance of drillhole is smaller, the pressure relief effect is better. When the distance between the drillhole is large to a certain degree, the area and efforts of the drillhole pressure relief will not change.(2) When using the same drillhole diameter and less drillhole distance to relieve coal pressure, the height of the pressure relief zone are the positive proportion relation to the depth of the coal seam. With the increase of the drillhole distance, the height of the pressure relief zone is not changed with the depth, basically tends to the same height. (3) When the drillhole parameters is same, the depth of the coal seam is greater, the pressure relief effect is better. At the same time in order to better prevent rock-burst, different buried depth of coal seam should choose reasonable drillhole parameters . (4) The results of simulation analysis is applied to 7192 working face in Xu Zhuang Coal Mine, who have played a very good pressure relief effect. The working face is ensured to be mined safely by using drillhole . The research conclusion can also provide scientific basis for roadway pressure relief for rock-burst prevention under different depths and the following working faces of Xu Zhuang coal mine being mined safely.