Based on nitrogen drilling testing in the goaf of Sihe coal mine, the necessity of drilling through the goaf in 3# coal seam to extract gas from 9+15# coal seam was proposed by analyzing the testing data of cores recovered from the coal seam. Based on “three band” theory, it was confirmed that there are drilling leakage zones present in 3# coal seam, which are located at 74.4m above the roof and 22.73m below the floor of the goaf respectively. Using nitrogen fluid to drill these zones can ensure drilling safety and improve the drilling efficiency. In order to meet the requirement of nitrogen drilling, the well structure with three sections and the surface drilling process were optimized. The successful application of the nitrogen drilling process in Sihe mine indicates that this process can be used in the goaf of coal mine, which provides an important guide for the research and application of drilling technology in goaf.