Abstract: In order to improve the resource recovery of 1202 (1) working face in Xieqiao coal mine, it is affirmed that the maximum height of the caving zone was 15.12 m, and the maximum height of the fissure zone was 52.78 m by using the methods of theoretical calculation and borehole detecting, and it is preliminarily determined that it was safe and feasible to extend the mining upper limit. The numerical simulation method was applied to simulate the water seepage rule in the overlying aquifer under the influence of adjacent coal seam mining. Numerical simulation study shows that the fissure zone cracks will be connected with the upper aquifer after extending the mining limit, and the water in the loose aquifer will mainly flow into the loose region at the bottom and the influence on the working face is limited under the action of the protective layer and goaf strata compaction. It is feasible to extend the mining upper limit in the field practice, and the economic benefit is remarkable with additional coal reserves 34000 t.