Abstract: To study the influencing factors of exhaust ventilation, using Standard k-ε calculation model, we use numerical simulation to study the influence of air volume, air duct diameter on wind speed distribution of exhaust ventilation in coal mine roadway, the ventilation tunnel is divided into: invalid area, pumping dust area, dust blocking zone area. The results show that the selection of dust suction for exhaust ventilation should be less than 4 m, the diameter of ventilator is not the main influence factor of exhaust ventilation dust removal; air flow is the main factor to determine the average wind speed in pumping dust zone, dust blocking area of roadway, and the effect of volume size on invalid area can be neglected.