Abstract: In order to study the laws of main characteristic gases and magnetism changing with temperature in the process of coal spontaneous combustion, we use coal spontaneous combustion experiment device to simulate spontaneous combustion of non-caking coal from Shenfu Mining Area, the discharge of characteristic gases under different temperature was tested, and magnetic susceptibility of coal samples under normal temperature and after heat treatment was tested by the improved Gouy magnetic instrument. The experimental results show that both of magnetic-field intensity and coal particle size have influence on coal magnetic under room temperature; before the dramatic change of coal magnetic in the process of spontaneous combustion, CO and CO₂ gas quantity increases gradually with the increasing of temperature; in magnetic dramatic change phase, when the coal magnetic susceptibility sharply increases with the increasing of temperature, the discharge of CO and CO₂ gas is stable until decline; 270 ℃ is the magnetic critical point of the coal, and C₂H₄ and C₂H₆ quantity increases rapidly near the critical point, and the fastest increased rate is at 300 ℃ to 350 ℃.