Firstly, the malodorous gas must undergo pretreatment, which involves removing the fine particles from the gas to be treated. Additionally, temperature and humidity adjustments must be made to suit the environment of the bio-odor removal box. Then, within the bio-odor removal box, there are numerous bio-fillers containing a large number of microorganisms. As the waste malodorous gas diffuses continuously and spreads to the outer water film of the medium, the pollutants are absorbed by the medium.

Microorganisms attached to the medium surface decompose pollutants into nutrients necessary for their growth and reproduction, as well as into non-polluting substances like carbon dioxide, oxygen, and water. This completes the bio-odor control box's treatment of the exhaust gas.