Abstract: Mined-out regions always bring enormous security hidden trouble to the residents lived in ore area.The model of a mined-out region underground in a mine of Hunan has been established and calculated by FLAC^3D,the displacement isoplethes of profiles of the model is made by self-compiled program,and the effect of mined-out region on ground subsidence has been analysized.The analysis result shows that the deformation of the roof of the mined-out region has significant influence on the ground surface and measures must be carried out immediately.Finally,the rational measures for treating the mined-out region are given to ensure the smooth and safe operation of the follow-up mining.