A numerical simulation has been carried out on the dynamic air environment of a surgical cleanroom in a Class II hospital, followed by an inquiry into the effects of ventilation mode and surgical illumination on the airflow characteristics and pollutant distribution in the operating room by using computational fluid dynamics (CFD) methods. The surgical illumination can result in a disruption of the unidirectional airflow path indoors, thereby enhancing the turbulent flow characteristics of the airflow. Whether for the overall space or local area of the operating room, the ventilation exhibits the best performance in the operating room when there is ventilation in the lower part with surgical illumination (Geo6) present. In the absence of operating illumination, the lower the position of the exhaust outlet, the higher the overall indoor pollutant concentration. In the presence of operating illumination, the higher the position of the air outlet, the higher the local pollutant concentration above the operating table will be.