In order to realize the efficient extraction of coal seam gas, this paper takes the 3203 working face of Dongfeng Coal Mine as the background to optimize the design of extraction boreholes. Based on the results of numerical simulation and field measurement, the technical scheme of gas extraction in working face is put forward by analyzing the gas source and ventilation mode of working face. The loose circle of surrounding rock was studied by drilling cuttings method and numerical simulation, and the sealing design was optimized. Finally, the extraction effect was analyzed by field measurement of gas parameters in the working face. The results show that the comprehensive extraction technology of coal seam pre-drainage, simultaneous drainage and mining, buried pipe in goaf and high-level borehole and the borehole sealing design based on the theory of surrounding rock loose circle can control coal seam gas well. The gas extraction amount is more than 54%, which controls the gas concentration of working face and roadway and ensures the safety of working face mining.