Abstract: To study the conditions generated of ammonium bisulfate in the reactor of selective catalytic reduction (SCR )catalytic at low temperature, rules of its deposition and enrichment, and its renewable technologies, a pilot-scale system of SCR reactor was designed and constructed based on the actual SCR project at low temperature. During the experiment, the distribution of NH ₃ or NO _x concentration could not be accurately measured which was axially along the catalyst or on the cross section of reactor,and which was more important to the experimental study. So a simulative model was created to follow kinetics of chemical reactions and computational fluid dynamics, whose correctness was verified by comparing consistency of the changing trends from experimental data and simulations, by different ammonia-nitrogen ratio, different temperatures and different rate of SCR set under the same conditions of reaction. The model can provide support for data analysis and research on the conditions generated of ammonium bisulfate in the reactor of SCR catalytic at low temperature, rules of its deposition and enrichment,while it could be used to simulate the process of catalytic reaction in the actual SCR project.