Abstract: According to the present situation of dynamic disaster under the conditions of horizontal slice mining of near- vertical and extremely-thick coal seam,the structures of roof,floor and coal were analyzed,and the mechanical model was established. The near vertical coal seam is clamped by the support pressure on both sides of roof and floor,the force source of clamping pressure which might result in rock burst was analyzed,and its expression of concentration de- gree and development trend was obtained by mechanical model solution. The stress distribution characteristics of the clamping coal were analyzed by numerical simulation and the theoretical analysis was verified. The results show that the stress concentration phenomenon occurs in the coal body from the level of the working face to about 70 m depth be- low. The pressurized area of the clamping coal is the direct hazard of rock-burst. Based on the analysis results,the pre- vention and control scheme of the rock-burst was put forward,which is to develop a heading for blast de-stressing.