Abstract: In order to analyze gas extraction drilling flow attenuation laws and reasons of Fuyan Coal Mine, the paper studies this by adopting the method of field test combined with theoretical analysis. Based on regression analysis of field test data, the paper obtained that gas extraction drilling hole flow attenuation law is in line with the logarithmic formula q_t=-39.989ln(t)+257.94 ,the correlation coefficient R²=0.941 5.It was thought that coal seam gas pressure reducing and drilling leakage are the mine reasons of pure flow attenuation.