The work aims to obtain the structure of the deflector in the suspension oven, which can improve the uniformity of the wind field and the air flow at the outlet of the air knife, to optimize the structure of the oven body. SolidWorks software was used to model the fluid field of the wind chamber of the oven and extract the field test data as the boundary condition. Fluent software was used to complete the simulation calculation of the steady flow field of the wind chamber. According to the calculation results, the structural optimization scheme was proposed and the optimization results were compared. The results showed that the uniformity of the wind field in the wind chamber of the oven and the air flow at the outlet of the air knife were improved after adding the deflector structure. Among the four structural optimization schemes proposed, the wind field in the wind chamber with curved deflector was more uniform. The average velocity variance of the air flow at the outlet of each wind blade was reduced from 0.25 to 0.03. The overall average uniformity of the air knife was increased from 80.7% to 92.3%. The guide effect of curvilinear structure is better than that of right angle structure. It can effectively improve the uniformity of the wind field in the wind chamber and the air flow at the outlet of the air knife, ensure the consistency of the drying effect of the pole piece, and provide a theoretical basis for the structural optimization and design of the oven body.