Abstract: The leica total station and GPS are jointly ussed for the surface horizontal displacement monitoring of mined-out area，and the triangle elevation method is adopted to make the vertical displacement monitoring，thus obtaining the horizontal displacement value and sinking cumulants of the cavity surface.On this basis，data processing can be realized with the aid of SURFER software to draw the three dimensional surface chart of ground surface settlement，three dimensional section map of the ground surface settlement，post diagram of the surface monitoring point.These drawings reflect the surface changing form，deformation range，settlement size and deformation trends visually.Based on the failure modes of surface movement，the surface horizontal displacement value and the accumulated value of settlement，the specific analysis results and the related recommendations are given.

Key words: 3D Visualization, Surface subsidence, Mined-out area, Displacement Monitoring