Due to the fact that the direct top plate of the coal seam of Shuangyang Mine is a huge thick water-bearing layer of cretaceous sand and gravel, all of them were evaluated as threat zones, with great possibility of large water, which cannot guide the production practice, double Packer stratified pumping system was introduced, the Cretaceous fractured aquifer was further divided into three layers, which were water-resisting layer, weak aquifer and medium water-rich aquifer. The safety of No. 4 coal seam Mining was evaluated and the water inflow was re-predicted, which provided the basis for the safe mining.