Abstract: In order to make a scientific evaluation of pillar stability and ground subsidence in the mining area under the condition of water-rock coupling in the process of mining，the uncertainty and randomness of engineering experience analogy method should be avoided.On the basis of engineering geological investigation，as well as physical and mechanical test of rock mass，applying the theory of the unity of the stress and displacement field，with the engineering background of Sijiaying iron ore，the engineering geological profile of ore block is used to establish fine 3D numerical model in the finite element numerical analysis software ANSYS.It imports the FLAC3D numerical simulation software for numerical simulation of the mine under the condition of the coupling.Finally the surface subsidence maps，the pillar stress cloud maps and the vector distribution of the seepage field were obtained.On the basis of this，the ground displacement，pillar stress and seepage field distribution characteristics in the process of mining excavation，are analyzed to predict deformation of overburden and surface，and the stress of pillar.Final results can not only provide certain scientific basis for mine mining process at present stage，and also has an important guiding significance for mine safety in production.

Key words: Upward horizontal sublevel filling method, Numerical simulation, Pillar stability, land subsidence, Water-rock coupling