In order to study the influence of the cone-column nozzle on the water pressure, and then the anti-reflection effect of the coal seam, Yungang Mine was taken as the research background, and rock mechanics theoretical analysis, numerical simulation calculation, and on-site effect inspection methods were adopted to study the form of nozzle. The research results showed that the energy of the water jet at the nozzle was the highest. As the distance from the outlet increased, the energy gradually decreased. The law of energy attenuation was symmetrically distributed on both sides of the axis. When the contraction angle was 30 °, the energy accumulation effect was significant and the energy attenuation was minimal The on-site inspection results showed that the gas extraction volume of the drilled field after cutting seams was greater than that of the uncut seam. The 6 m and 8 m drainage radius inspections showed that the gas drainage pure volume of 8 m was 0.06 m3 / min more than the extraction radius of 6 m. Considering economy and applicability, the extraction radius of 6 m was adopted.