The exhaust pipe of the range hood is unstable, which will cause vibration between the range hood and the wall during operation, thus generating noise. The solution is to re-fix the exhaust pipe so that it is completely close to the wall, so that there will be no vibration. 1. The range hood is not installed firmly. If the position is uneven, the screw is loose, and the parts fall off, resulting in vibration with the bracket during extreme work, it is necessary to reinstall the range hood or parts, and the position must be estimated to ensure correct installation. 2. The check valve is not installed correctly. For example, the one-way valve fails and falls off, which leads to poor smoke exhaust effect, and the oil smoke in the pipeline is disturbed by the vibration of the one-way valve or the airflow, which is easy to produce noise. At this time, the check valve should be reinstalled or replaced with a new one. 3. The blades of the wind turbine are deformed and improperly installed. Due to long-term use, a large number of oil stains are attached to the wind wheel, which leads to imbalance or some blades are broken, which will produce noise. At this time, the range hood should be cleaned regularly and the wind wheel should be replaced if necessary. 4. The range hood and pipes have not been cleaned for a long time. Flue and range hood have long-term oil stains and foreign bodies, and the fan is unstable and noisy. In this way, it is necessary to clean the range hood and pipes regularly to maintain normal air circulation. The air in the kitchen is not circulating and closed. This leads to poor convection between the range hood and the pipeline, negative pressure can not be formed inside the kitchen, poor exhaust and loud noise. So the kitchen must avoid ventilation.