In order to effectively reduce the mass concentration of the particles and improve the air cleanliness level in the operating clean room in the expandable shelter vehicle, the diffusion particles in an non-unidirectional flow clean operating room are analyzed. The minimum mass concentration of the particles in the working plane is set as the goal, and the optimization model is established with the average wind speed of the working plane, as the constraint condition. The sequential response surface method is used to optimize the velocity and the angle of supplying the air. It is shown that when the outlet of the operating room is arranged symmetrically on the long side wall, the flow of the indoor air could be well activated to reduce the mass concentration of the particle. In the non-unidirectional flow operating room, the mass concentration of the particles is mainly affected by the flow of the air. When the dominant diffusion direction of the particles is changed to the downwind, the mass concentration of the particles in the main flow area is relatively low and the mass concentration of the particles in the surrounding area, around the area of the medical staff and the wall of the operating room, may be larger. With the velocity and the angle of supplying the air optimized by the response surface method, the mass concentration of the particles could be reduced by 78.19% to make the air quality of the operating room reach the clean standard. Also, this optimized method helps the ventilation design of the vehicle operating room.

response surface method  /  clean operating room  /  particle mass concentration  /  speed of supply air  /  angle of supply air  /  parameters optimization