Abstract: The study found that some irritating odor gas will be generated in the process of sewage treatment, which is easily discharged in large quantities during the dehydration and drying of sludge. The malodor caused by it not only pollutes the environment but also affects the staff and surrounding residents. Healthy body. In order to optimize the mechanical ventilation of the machine room and effectively discharge odorous gases, this paper takes the sludge dewatering machine room of the Bailonggang Sludge Phase II project as the research object, and analyzes and calculates the different locations and different ventilation conditions in the machine room during the sewage treatment process through numerical simulation The concentration value of polluting gas in the environment, and on this basis to realize the analysis of the airflow distribution and the overall airflow field distribution in the environment, and propose an optimized design scheme for mechanical ventilation of the sludge dewatering machine room to guide the sewage treatment plant to Collection and treatment of malodorous gas.