Abstract: The thermal conductivity is an important parameter affecting the heat conduction of coal. In order to research the heat transfer characteristics of coal under the conditions of different temperatures and moisture contents, LFA457 laser thermal conductivity testing instrument was applied to measure the thermal conductivity of non-caking coal and gas coal under the conditions of different temperatures and moisture contents, and the influence of the internal factors of coal on its thermal conductivity was analyzed by using the Deng's grey theory. The results showed that when the temperature was -50℃ to -30℃, the thermal conductivity of coal decreased rapidly; when the temperature was -30℃ to +10℃, the thermal conductivity of coal increased rapidly; when the temperature was +10℃ to +50℃, the thermal conductivity of coal tended to slowly increase; and with the increase of the moisture content of coal, the thermal conductivity started to increase rapidly, and then tended to be stable. The grey correlation analysis showed that the fixed carbon, ash and volatile matter of coal were the main factors affecting its thermal conductivity.