Abstract: The front technology of biomass pyrolysis used for biomass energy research and development has been more widely appreciated. The pyrolysis characteristics and dynamics of corn stalks by steam explosion pretreatment were studied using the thermal gravimetric analysis (TGA) method under different heating rate, i.e., 10℃, 20℃, 30℃, 40℃ and 50℃/min.The terminal temperature was 800℃ and the high-purity N2 was used as reacting and protecting gas.The results indecated that the pyrolysis characteristics and parameters of corn stalks by steam explosion were significantly changed, and maximum thermal decomposition rate increased by 34.57% under the same heating rate. Thermogravimetric dynamic parameters of samples were calculated by the methods of Coats-Redfern and Kissinger，respectively; activation energies of treated corn stalks reduced 24.13%-32.56% compared with corn stalks，and frequency factor improved 8%-10%.