The radius of coalbed methane extraction is influenced by multiple factors, It is difficult to determine the effective extraction radius, This article uses theoretical analysis and underground measurement methods to analyze the attenuation characteristics of drilling flow rate and derive the maximum extraction time of drilling,When the coal seam gas extraction rate is ≥30%, the calculation formula for drilling extraction radius is obtained, which provides a basis for the design of pre extraction drilling holes in this coal seam,The main conclusions are as follows: 1) The negative exponential relationship between drilling gas extraction flow rate and time is as follows: q1=0.081e-0.028t，q2=0.102e-0.033t，q3=0.093e-0.038t, The attenuation coefficient of drilling gas flow is 0.028～0.038d-1,The maximum extraction time for drilling is 78.9～107.1d, and the coal seam has moderate permeability. 2) When the extraction time is 120d, the calculated extraction radius is 2.26～2.45m,The pre pumping time measured by the pressure drop method is 115d, and the pumping radius is 2.25m. 3) When the extraction radius is 2.25m and the extraction time is 120d, the maximum value of residual gas content after pre extraction is 4.96 m3/t, which meets the requirements of the extraction design, The gas pressure decreased by 53.85～83.33%, and the extraction rate was 34.22～60.61%, and the desorption gas content after pre extraction is 1.26～3.30m3/t, which meets the relevant requirements for extraction standards. 4) When the drilling diameter is133mm, the drilling distance is 4.5m, extraction negative pressure is 15~20kPa, pre extraction time is 120d, During the mining period, the gas concentration in the upper corner is controlled at 0.12～0.43%, gas control effect is significant, The relevant research has guiding significance for the design of pumping in working faces with similar geological conditions.