In order to solve the problem of drying products varying greatly in quality which was caused by uneven distribution of airflow inside the chamber of dryer, under different parameters the airflow in drying chamber is stimulated and analyzed by combination of FLUENT software and orthogonal experiments. The air velocity was considered as an evaluation indicator. In addition, the result of evaluation indicator was analyzed by combination of extreme difference analysis and standard deviation and therefore the optimum parameter combinations could be obtained and numerically stimulated. The results show that when the distance of baking sheets in the dryer, the size of air outlet and the velocity of inlet air are 10 mm, 1 000*230 mm and 4.5 m/s respectively, the drying effect is excellent, which can provide theory gist for research on optimizing design parameters of the dryer.