Closed poor boreholes connecting with aquifers to varying degrees, it was a special vertical structure of artificial water-conducting channels in mines. It was widely distributed in coal mines and was extremely harmful to the safety of coal mines. Poorly closed boreholes have been formed due to the limitations of drilling and sealing materials, processes, and lax construction management. Proper drilling was first performed when the poorly sealed boreholes were unsealed. In the case of mud sections, punching was used, and the cement slurry consolidation body was used with core drilling tools. Detecting comprehensive boreholes, grouting was completed and the grouting was closed. The grouting materials, process, pressure, and construction organization were specially designed to meet the requirements for prevention and treatment of poorly sealed boreholes and had an important role in solving the poorly sealed boreholes.