Abstract: In order to explore the key factors affecting cabin noise, orthogonal experiments were designed to analyze the cabin noise level under the combination of fresh air volume and pressure at different levels. The depressurization process of the low-pressure chamber was simulated by fluent, and it was found that the fresh air volume was the key factor affecting the noise in the low-pressure chamber. The results show that the frequency range of cabin noise is mainly concentrated in the range of 20 Hz～500 Hz, and the experimental results are compared with the simulation results, and the results tend to be consistent, which verifies the reliability of the simulation method and provides a reference for reducing the cabin noise and optimizing the cabin environment.