Abstract: The coal in the goaf not only seriously affects the safe production of coal mines, but also causes serious pollution to the ecological environment. Therefore, the determination of the location of the high-temperature heat source in goaf becomes a key problem in the process of working face advancing. In this paper, the relationship between the thermal conductivity under different voltages with the heating voltage （U） and the working temperature （t_m） is analyzed. Then, the steady-state heat conductivity model of the sphere is established, and the location and temperature of the high-temperature heat source point in the goaf are calculated by combining Fourier’s heat conductivity law. The results show that the heat conductivity under different voltages had a linear relationship with the heating voltage （U） and the working temperature （t_m）, and the fitting degree is good. The distance between the location of the high-temperature heat source in the goaf and the top of the roadway perpendicular to the heat source point is 3 m, and the temperature of the high-temperature heat source point is 38.5 °C. The main reason for the error may be the observation error caused by system error and human factors. In the selection of cooling methods, by comparing different cooling methods in goaf such as injecting inert gas to reduce oxygen and temperature, injecting grout, injecting colloid, spraying inhibitor, and so on, combined with the site conditions of the goaf in coal mine and the technological and economic applicability of the materials, it is finally decided to use the comprehensive cooling method to cool the high-temperature area of the goaf to ensure the safe and efficient production of the mining area.