Abstract: In order to study the influence of coal seam thickness change occurred in the process of mining on rock burst probability, FLAC^3D numerical simulation is used to simulate the distribution laws of abutment pressure elastic strain energy of different coal thickness and coal thickness change area length in thickness change area. The result shows that the larger of the coal seam change rate is, the higher of the stress concentration in local change area and more probability of rock burst will be when the length of coal seam change area is the same in the process of coal thickness changing from 8 m, 6 m,4 m to 1 m; the larger of the change area is, the lower of stress concentration in the area will be when the coal thickness is the same in the process of local change area changing from 10 m to 30 m. In other words, the probability of rock burst in coal thickness change area is positively correlated with the increase rate of coal thickness, and shows a negative correlation with the increase of coal thickness change area length.