Abstract: As a key component of the residual film barrier device, the air distribution chamber has the function of optimizing the flow field structure and uniform air curtain. Under the condition that the external structure of air distribution chamber is difficult to be further optimized due to the limitation of assembly space, the optimization of jet outlet structure parameters has a positive effect on improving the uniformity of air distribution in air distribution chamber. In order to improve the uniform stability of the jet curtain of the residual film barrier device, the velocity nonuniformity coefficient was used as the evaluation index, based on fluent, the range of influencing factors was determined by single factor experiment. Combined with second-order response surface method and non-dominated sorting genetic algorithm-II（NSGA-II）, the optimal design parameters were obtained as follows: X₁=70 mm, Y₁=2 mm, X₂=160 mm, Y₂=2 mm, compared with the original device, the uneven coefficient of jet outlet velocity was reduced by about 28.6% and 25.9%, respectively. The experimental results showed that the maximum velocity deviation of two jet exits was 8.3% and 14% respectively, and the distribution trend of jet exit velocity was in good agreement with the simulation value.