Abstract: Local ventilators are prone to experiencing transient airflow interruptions during switching operations,which may induce the gas concentration to exceed the safety threshold. For this reason,based on the theory of constant airflow switching,an intelligent constant airflow switching control system for local ventilators is constructed,and a comprehensive aerodynamic performance evaluation is carried out for the core links of the ventilator fan system,i. e.,four key parts,i. e.,the air inlet,air velocity monitoring point,and collector inlet and outlet channels. The results show that the full-pressure efficiency index stably stays within the high-efficiency range of 82.5% to 85.0%, which fully verifies the advancement and effectiveness of the system design. The results show that the airflow fluctuation of ZFJ1140 local ventilator during the airflow switching process is accurately controlled within 8. 89%, which is significantly better than the traditional ventilator switching method.