With the development of urbanization, the number and scale of sewage treatment plants are increasing, and the effective collection of odor generated by them is of great significance to prevent odor leakage, protect the environment and reduce energy consumption. The influence of structural parameters (different tube bundle positions, different tube bundle numbers, different pipe diameters) and operating parameters (suction flow) on the internal flow field of the odor collection hood of a sewage treatment plant was studied by numerical simulation. The results show that when the tube bundle is placed at the very edge of the air collecting hood, the number of suction pipes is three, the diameter of pipe is 150 mm, and the suction flow range is 3.63 kg/s to 5.71 kg/s, the airflow structure in the cavity is the best, the odor concentration is the lowest, and the suction effect is the best.