Abstract: In order to obtain the causes of the mine pressure bump occurred in Yima Coalfield mines, and set up effective measures to prevent and control the min e pressure bump, this paper had a study on the geological structure, deep mining depth, ultra thick hard conglomerate roof, structure stress and other geological factors of the coal seam with hard seam and hard roof and soft floor in the coalfield affected to the role of the mine pressure bump. The paper pointed out that the depth of the seam in the syncline axial core was up to 600~ 1 200 m and the thick overburden strata and the ground stress concentration were the main causes of the mine pressur e bump occurred. The paper provided the enhanced gateway support and the deep borehole water injection and the pressure releasing blasting conducted along the tw 0 sidewalls of the gateway thus to make the surrounding rock of the gateway form a"two hard and one soft' 'support structure and to avoid the coal mining strike verticall y to the main stress direction of the structure and other measures to prevent and control the mine pressure bump. The results showed that the mine pressure bump in Yi ma Coalfield was a gravity- structure type and after the related comprehensive measures conducted, the frequency of the mine pressure bump was reduced.