Step test method, which is a kind of commonly used industrial process identification method, has the disadvantages of time-consuming and production disruption. For this reason, this paper takes the sensitive tray temperature control system of the s-trioxane concentration column as the research object, and the step test models and experience models are obtained, and the two kinds of model predictive effects are simulated and compared. Finally, a MPC controller based on experience models is designed and put into operation. The actual plant application shows that the MPC controller could effectively improve the stability of the sensitive tray temperature.