Abstract: The development process of coal spontaneous combustion in the actual site is very complex, and the spontaneous combustion process is affected by many factors. One of the key points is the temperature change of fire source. In the actual working conditions, the location of fire source is often hidden and difficult to find, making it difficult to track and determine the direction and region of temperature change. Therefore, in the experimental environment of room temperature and room pressure, the temperature of coal spontaneous combustion is monitored, and the temperature change law under the inclined placement mode is analyzed to determine the high temperature area and its spread fuzzy path, and further analyze the influence of fire air pressure on the temperature change in the high temperature area. The study shows that the spread of high temperature area is nonlinear, mainly along the central and southeast direction of the furnace body. In the early stage of the experiment, the influence of temperature on the fire heating air pressure occupies the main position, while the elevation difference plays the leading role in the size of the fire heating air pressure. The temperature change of the shallow coal sample is mainly affected by thermal conduction. The temperature change of the upper coal sample is not only affected by thermal conduction, but also affected by the cracks produced by combustion, and the lower coal sample is also affected by fire air pressure, resulting in the gradual decrease of temperature with the deepening of the number of layers.