Abstract: Shendong mining area, located in the arid and semi-arid areas, is an important coal origin in China, where the overburden structure has characteristics of shallow seam, thin bedrock and thick windblown sands, thus, the green mining (especially water preserving mining) has important significance in this area. Based on the failure characteristics of different rock strata, combining with the analysis of deformability, bearing capacity, and physical quantities associated with mining, a mechanical model predicting the height of water-flowing fractured zone(WFZ) is given, which is further used to analyze the height of WFZ in LW12610 of Daliuta coal mine. Both the results of numerical simulation and field observation show that the mechanical model is advisable.