Abstract: As the basic work of fire prevention and control in coal mines, detecting and finding out the high temperature area are one of the preconditions of making fire prevention plan. In this paper, the temperature field of coal wall in roadway is tested by infrared thermal imaging, and the high temperature area of the coal is checked out compared with airflow temperature. The result shows that the high temperature area is mainly concentrated nearby a fault zone, from which it can be known that the crushed coal and air leakage are the major causes to induce spontaneous combustion. According to this finding, the measures of injecting MEA into the high temperature area have been taken, making CO content decrease from 100~160 ppm to10 ppm.