Abstract: In order to meet the need of accurate airflow control in hospital operating room, biochemical laboratory and clean room, an airflow control valve with a mechanical, pressure-independent regulator was developed. Adjusting the flow area of the regulator automatically, the valve was designed to be able keep the air flow in a pre-established value, being unacted on duct pressure varies. Based on the CFD technology, the flow field of the airflow control valve was modeled and simulated to analyze the influence of the key structural parameters on the flow field characteristics and carry out optimized design of the valve. And a testing device was built for the airflow control valve to verify the performance of the pressure independent valve.