Abstract: In view of the problem that the local resistance between the air chamber and the fan was not considered in the current prediction method of air volume and pressure at the working point of the ground main fan, which would lead to the decrease of prediction accuracy, in order to improve the accuracy of the prediction of the working point of the main fan on the ground, Based on the prediction of air volume and pressure at the working point after replacing the ground main fan in No.2 air shaft of Shiyaodian coal mine of Shenmu coal industry, three methods of measurement, numerical simulation and theoretical formula were used to calculate the local ventilation resistance between the wind tunnel and the fan respectively. The research showed that the numerical simulation method could accurately calculate the local ventilation resistance between the wind tunnel and the fan. On this basis, the nonlinear calculation formula of the local ventilation resistance between the wind tunnel and the fan was established. Combining the measured wind volume and pressure characteristic curve of the fan and the mine ventilation Based on the resistance characteristic curve, the prediction equation of the air pressure and air volume operating point of the main fan was established considering the influence of the local resistance between the air chamber and the fan. The relative errors of the air volume and air pressure between the calculation results of the prediction equation without considering the local resistance between the wind tunnel and the fan and the actual operating point were 8.66% and 12.18%. The relative errors of air volume and air pressure between the calculation results of the prediction equation considering the local resistance between the wind tunnel and the fan and the actual operating points are reduced to 4.12% and 5.57%. The research showed that the local ventilation resistance between the wind tunnel and the fan had an important effect on the working point of the main fan on the ground. Considering the influence of the local resistance between the air chamber and the fan, the prediction method of the working point of the main fan could improve the accuracy of the air volume and air pressure prediction to a certain extent Sex.