Abstract: In order to reduce the air flow test error of the mine ventilator during the performance test process of the mine main ventilator in the coal mine, based on Bernoulli equation suitable for the quasi-steady flow, from the theory, a comparison and analysis was conducted on the test precision between the static pressure difference method and the dynamic pressure method. Taking the main ventilator of East Ventilation Mine in Baiping Coal Company as the experiment object, the static pressure difference method and the dynamic pressure method was individually applied to the measurement of the air flow of the main ventilator and the comparison analysis was conducted on the measured results. The study showed that the site measured air flow results of the two methods had a relative error both less than 6%,the accuracy could meet the requirements of the site production,but in the static pressure difference method, the local resistance loss could not be determined and the uneven layout of the measuring points would cause big measurement error. The accuracy of the calculation results by the static pressure difference method was less than the dynamic pressure method.Therefore,from the consideration of the precision, the dynamic pressure method should have the first priority to be applied to measure the air flow of the ventilator.