Abstract: In view of the problems of small dam structure, large buried depth of coal seam and large ratio of dam structure height to buried depth of coal seam, it is difficult to calculate the movement and deformation law of dam structure by conventional methods. It is proposed to separate the movement and deformation of the surface and the dam structure, quantitatively analyze the movement and deformation of the dam structure under the surface movement and deformation, obtain the movement and deformation law of the dam structure with different advancing lengths of the working face, and establish the space-time sequence inversion mechanism of local amplification of the dam structure in deep coal seam mining under the dam. Taking the mining of the working face under the dam of a mine as an example, the research results show that the maximum subsidence value of the dam body obtained by numerical simulation is 7.17 m, and the absolute error is 0.093 m compared with the measured result of 7.077 m.