Abstract: In order to achieve the mechanism of surface subsidence of longwall mining mine with thin buried-depth and large mining height in loess area, taking a working face of Daliuta Coal Mine in Shaanxi Province Yulin City, according to theoretical analysis, we use UDEC4.0 numerical simulation software to study mechanism of surface subsidence. The results showed that the error comparing with measured results is small and parameters such as subsidence coefficient, main influencing angle of stratum, the range of subsidence basin, ground surface tilt and curvature are figured out, which revealed the general development laws of overburden deformation and surface subsidence in Daliuta 2^-2 coal seam.