Abstract: Exploration of underground minerals usually results in surface cracking，surface deformation，and damage to buildings，which has a serious impact on people′s production and life.Surface deformation in mining area is always an important aspect affecting mining safety.FLAC3D software was applied to build a three-dimensional geological model for simulating the surface deformation caused by the upward horizontal slicing and filling stoping in Sijiaying Iron Mine and a contrast with the surface subsidence value calculated by the empirical formula was made.Thus，the general rule and the deformation mechanism concerning surface deformation in Sijiaying Iron Mine were put forwards，and the geological hazards of surface deformation were assessed.The results showed that the upward horizontal slicing and filling stoping method effectively controlled surface deformation and the filling body played an important role in reducing deformation.The contrastive analysis showed that the numerical simulation result is smaller than that by the empirical formulas，but still within a reasonable limit permitted，indicating that FLAC3D is an effective way of predicting surface deformation.The research has important reference value for research and prediction of surface deformation caused by other similar mining method.

Key words: Upward horizontal slicing and filling stoping method, Surface deformation, Numerical simulation, Empirical formula