Abstract: To address the problems of large gas emission volume, complex gas sources, and high difficulty in gas control in goaf areas of coal-oil-gas coexisting mines, this study takes the No.405 fully mechanized working face of Nanchuan No.2 Coal Mine in the Huanglong Coalfield as the engineering background. Based on the actual mining conditions, systematic research on gas source identification in the goaf and gas drainage technology using high-level fractured boreholes is carried out by means of field investigation, theoretical analysis, parameter testing, engineering implementation, and effect verification. Through the test of coal seam gas parameters and the statistical analysis of gas emission in the working face, there was a significant difference between the predicted gas emission of 1.06 m³/min and the actual total gas emission of 12.93 m³/min, and the difference was as high as 11.87 m³/min. It was identified that the gas in the goaf was mainly derived from the surrounding rock affected by mining. Based on the theory of 'three zones' and ' O '-shaped circle of overlying strata migration, the key parameters of high-level fracture drilling are determined: the vertical height of the final hole is 30 m, the horizontal distance is 35 m, the opening inclined angle is 30°, the hole depth is 60 m, and the spacing is 3 m. The on-site construction adopts the 'two plugging and one grouting' pressure sealing technology and orifice blowout prevention system, with a total of 94 construction boreholes and a footage of 5640 m. The extraction effect shows that the concentration of borehole extraction is up to 48 %, and the pure amount is up to 3.0 m³/min. After the implementation of drainage, the gas concentration in the upper corner of the working face is significantly reduced from 0.2 % -0.7 % before treatment to 0.1 % -0.4 %, which effectively controls the risk of gas overrun.