Abstract: An engineering geological model is established by taking the 9418 working face in a mine No.9 coal as an example.On the basis of analyzing engineering geological,hydro-geological and mining conditions of the mine,the finite difference software of FLAC^3D is utilized to simulate the mining and damage laws of the roof and floor caused by working face advancing.The basic development changes laws of the stress field,displacement deformation and plastic failure zone of the roof and floor during the process of working face advancing were obtained.And this would provide preference for the mining safety and the prevention of the water-inrush.