Abstract：In order to study on characteristic temperature and risk level of coal combustion, temperature range of coal at each phrase and characteristic temperature of coal were determined by thermogravimetric experiment. Using Freeman-Carroll differential method, the reaction mechanism function were established, and preexponential factor and activation energy were solved. Its change law of characteristic temperature, preexponential factor and activation energy were analyzed. The results show that the temperature range of six coal samples at combustion phrase are 247℃～433℃, 280℃～537℃, 279℃～542℃, 272℃～550℃, 313℃～574℃ and 365℃～594℃. With the increase of fixed carbon, coal combustion process and characteristic temperature are suppressed, preexponential factor and activation energy increase. No.1 coal sample is the easiest to spontaneous combustion, and No.6 coal sample is the hardest to spontaneous combustion. T1 increases from 247 to 365℃, T2 increases from 386 to 479℃, T3 increases from 408 to 514℃, T4 increases from 433 to 594℃.