Abstract: Permo-Carboniferous coal seam of Datong coalfield is thick spontaneous combustion seam,the silicified coal formed in the upper part of 3^# to 5^# coal seams of the Taiyuan Formation by igneous intrusion is easily spontaneous combustion.Aiming at the fire forecasting problem in No.1 panel of Tongxin coal mine,the paper researches the spontaneous combustion laws of the mine,determines the spontaneous ignition temperature by using thermal gravimetric analysis method,analyzes the remarkable gas in different temperature by spectroscopic analysis and finally determines a two levels forecasting system taking CO,C₂H₄ as indicator gas.The spontaneous combustion monitoring system that takes beam tube as primary means is established.