Abstract: According to the problem that airflow measuring air volume of mine ventilator with the air velocity method was affected by support, therefore taking a min e circular roadway as a case, based on the analysis on the internal airflow distribution law of the mine roadway, a Fluent software was applied to establish a simulation model of the mine roadway.A numerical simulation was conducted on the airflow field in the mine roadway under the two conditions with no stand and the stand individu ally and the airflow value of each measuring point was obtained.The simulation results were obtained from the comparison between the two conditions. The stand install ed in the mine roadway could make the cross air velocity measured value varied.There was a deviation between the measured value and the actual value, the max relat ive error would be 12.3% and the average relative error would be 5.7%.The study could provide the basis to improve the airflow measuring method of the mine main ve ntilator and to compensate the error.