Abstract: Due to the high gas emission , In order to solve the problem of the existing wind measures is difficult to control and extraction of measures to reduce the gas quantity problem. This pape ruse t theoretical calculation and numerical simulation to analyze the development regularity of roof mining fissure and found that the width of annular thin coal seam working face roof fissure is smaller and can't make the upper part and the key layer breaking, above makes the key stratum and rock in the enrichment of transfixion crack gas can't development. Therefore extraction project layout should be under the key stratum fissure zone, and according to the analysis of the extraction from engineering design and achieved good application effect.