Thermal analysis curves of black powder and its raw materials were measured with heating rates of 5,10,20 and 40 ℃·min^－1 by differential scanning calorimetry (DSC) and thermogravimetry (TG). Thermal decomposition of black powder was discussed based on experimental data. The functions of sulphur,charcoal and KNO₃ were demonstrated when black powder was heated. Moreover,according to Kissinger equation,activation energy and pre-exponential factor of black powder were calculated to be 98.5 kJ·mol^－1,173.4 kJ·mol^－1 and 5.6 s^－1,11.1 s^－1,respectively.