Abstract: A novel chemical kinetics model was established to describe the combustion processes under the theoretical basis of elementary reaction of NO_x formation and reaction kinetics. The NO_x formation process was simulated by the new model with the CFD software, and the results were in good agreement with the experimental data. It can be concluded that the new established model is better than the equilibrium model and partial equilibrium model provided by the FLUENT module, when they are used to calculate the combustion processes.