The mechanisms of pyrolysis of corn stalk were investigated by means of both model method and model-free method，and following the idea of dual extrapolation method at the same time.Firstly，a thermogravimetry experiment was performed to investigate the process of pyrolysis of corn stalk，in nitrogen gas and at various heating rates.Secondly，an analysis，combining model method and model-free method，was utilized to understand the mechanisms of pyrolysis of corn stalk.The several mechanisms were screened by means of the Popescu method.Then，the kinetic parameters are obtained by the integral formula proposed by Tang and the iso-conversion methods respectively.Moreover，the aforementioned results are all extrapolated following the idea of dual extrapolation method.It is found from the comparison that 2 mechanisms are both probable to satisfy pyrolysis of corn stalk.Furthermore，a preliminary comparison was carried out between the results from the two models and the experimental data.According to the comparison，combined the status of pyrolysis research of biomass，it was concluded that the mechanisms for corn stalk follow reaction of 2.5-order.And it was obtained that the activation energy，97.72 kJ·mol-1，and the frequency factor，3661231 s-1.Finally，an analysis was conducted concerning the discrepancy between the calculation and the experiment.