Dust-containing gas enters the dust chamber from the inlet of the bag filter under the action of negative pressure of the fan, and through the filtering action of the bag, the dust is separated from the airflow, and the clean gas purified through the filter bag enters the clean air chamber, and is discharged by the fan. Dust removal is mainly to improve the office environment, to give employees a good working atmosphere, to protect the health of employees, that is, the use of fans to send air or exhaust air, the air to enhance the circulation, so as to maintain a comfortable working environment.