Introduction: This is an application-based article. Objectives: In order to solve the problem of uneven drying inside the drying chamber of the existing silica sol shells and improve the drying quality of the shells, the structural optimization is carried out by means of numerical simulation. Methods: Numerical simulation of the flow field in the drying chamber is carried out based on the standard k-ε model, according to the simulation results, the distribution characteristics of the flow field in the drying chamber of the two airflow organization schemes are compared and analyzed, and the structural optimization scheme of installing a deflector plate is put forward, and the parameter optimization test is carried out by applying the orthogonal test method to obtain the optimal design parameters of the deflector plate: width of the deflector plate is 225 mm, the angle is 30°, and the spacing is 150 mm. Resutts: The results show that the velocity and temperature distribution of the upper and lower air supply mode is more uniform than that of the upper and lower return mode, so we choose to add the deflector plate to the upper and lower air supply drying chamber to further improve its uniformity. After optimization of the structure, the velocity non-uniformity coefficient decreased by 16%, and the temperature non-uniformity coefficient decreased by 0.3%. Conclusion: The temperature distribution and speed distribution in the drying chamber optimized by the structure are more uniform, and it can be applied to the hot air drying of silica sol shell.