Abstract: By applying theory analysis and similar simulation method, the mining rock movement and failure laws and development characteristics of "two zones" are researched, and the stratigraphic structural model of waterproof pillar is built based on the structure of Cenozoic alluvium and it's permeability in Xieqiao Coal Mine. Meanwhile, the seepage field of overlying strata under the influence of adjacent coal seams mining is acquired by using numerical simulation method when the mining upper limit of 1202 (1) face is different. The research shows that the plastic zone will further develop and spread to upper aquifer after narrowing the waterproof coal pillar, but its density is relatively rare. The development of seepage path is not continuous under the action of protective layer and goaf strata compaction. Therefore, the water of aquifer infiltrating to the face is limited, and it is safe and feasible to narrow the waterproof coal pillar and the liberated coal is 35 000 t.