Abstract: Based on the actual geological data in Gushuyuan coal seam, the overburden failure of 15# coal seam under goaf is analyzed by the RFPA^2D analysis software, the 15^# fissures situation of hard roof after mining is observed and the development height of the three zones in mining overburden rock are researched, the results are analyzed from movement and failure laws of overlying strata, the displacement and stress variation of 15^# seam roof. With the distribution laws research on the 15^# coal seam, the contour maps of mine caving zone and water flowing fractured zone height are compiled, and the maximum growth height of water flowing fractured zone of 15^# coal seam is determined. There is the infiltration possibility of water in 9^# coal seam goaf during the mining process of 15^# coal seam. According to the fissures development situation, combining with roof lithology, the paper provides the basis for establishing drainage system and controlling gas in 15^# coal seam.