Abstract: In the process of coal stacking, oxidation and exothermic reaction are easy to occur, which leads to spontaneous combustion of coal piles, wasting of resources and environmental pollution, a gravity heat pipe was inserted inside the coal pile, phase change occurs in the heat pipe with high thermal conductivity to timely transfer heat to the air to prevent spontaneous combustion of coal piles. Based on the theoretical analysis and the numerical simulation of Fluent software, the effect of the gravity heat pipe on the temperature field inside the coal pile was studied. The results show that the closer the heat pipe is to the heat source, the better the cooling effect. When the inclination angle of the gravity heat pipe inserted into the coal pile is 60 °, the cooling effect is better; the cooling effect on the outside of the heat pipe is lower than that on the inside of the heat pipe.