The layout of cross-layer boreholes is one of the important factors affecting the efficiency of gas extraction. In order to study the effects of the layouts of cross-seam boreholes on gas extraction, gas control roadway 2121(1) in the Pansan mine was taken as the research object in this paper to analyze the effects of the three kinds of layouts of cross-seam boreholes, 10×5, 8×6 and 7×7, on gas extraction. The gas-solid coupling model of coal seam based on fracture-pore dual media was established, and the gas extraction processes of the three kinds of borehole layouts were simulated numerically by using finite volume method and Newton iteration method. And the engineer quantity of boreholes and the average pure gas flow volume extracted in the 30 days were investigated at the field. The results show that the "blank zone" area of the borehole layout 8×6 and that of 7×7 are smaller obviously than that of 10×5 under the same time of gas extraction. And the extraction time required for the elimination of "blank zone" is less than that of the borehole layout of 10×5. So, the borehole layout of 10×5 is bad for eliminating gas outburst. The engineer quantity of the borehole layout of 8×6 is the smallest and that of the borehole layout of 7×7 is the largest. The average pure flow volume daily by single borehole of the borehole layout of 7×7 is larger slightly than that of the borehole layout of 8×6, and that of the borehole layout of 10×5 is the smallest. The results of the numerical simulation and the field experiments considered, it is obtained that the borehole layout of 8×6 is the optimal. The result of this study provides a good guidance for the design of cross-seam boreholes in a coal mine.