Abstract: Four shafts and shaft mouths were closed due to the fire accident in the coal mining face in Yanjing No.1 Coal Mine. In order to effectively and quickly extinguish the underground fire area, prevent the secondary accident of gas and coal dust explosion caused by the spread of mine fire due to the outburst with high gas content, and finally realize the safe unsealing of the mine, the Sherm drilling rig was used for construction. Two accurately positioned vertical boreholes were constructed at the corresponding positions of the high-temperature fire points in the underground fire area, which respectively penetrated the caving zone of the upper goaf of the coal mining face. In the field construction process of ground drilling, accurate positioning and safe construction were realized on the site, and the casing was successfully lowered. The construction was confirmed to be in place through borehole observation and detection. The application can provide guidance in equipment, technology and process support for large flow liquid nitrogen injection and curtain grouting plugging during the fire extinguishing process.