Abstract: To solve the problem of controlling concealed fire source of typical small kilns in Datong Mining Area, the combination method of experimental analysis and infrared thermal imaging technology is adopted to study the detection and control technology of concealed fire source, i.e. through the programmed heating experiment, it is found that compared with the traditional grouting fire-proof material, the large aggregate accumulation isolation materials is more effective in inhibiting the increase of coal temperature and reducing the concentration of spontaneous ignition signature gas, and the infrared thermal imaging and drilling techniques are used to delineate concealed fire sources. The large aggregate accumulation filling materials are injected into the area suspected to be the fire source, and the materials have the characteristics of fast coagulation, easy formation and high strength, so the isolation strip is quickly constructed to gradually suffocate the fire area. The results show that the infrared thermal imaging technology can be used as an effective method for detecting and delineating concealed fire sources. At the same time, large aggregate accumulation and isolation filling materials can not only effectively prevent small kiln fire from invading the main mining face, but also cut off oxygen supply in the fire area to achieve the purpose of asphyxiating the fire area.