Abstract: The speed of ventilation will directly affect the dispersion of dust particles, which will reduce the visibility of the roadheader driver and lower the operational efficiency.The CFD-DPM method was used to study the air flow and dust dispersion law of coal mine roadway under different ventilation air speeds, and the results show that the obstruction caused by roadheader will cause the airflow to carry dust particles along the roadway wall from the disordered area into the recirculation area, and due to a sudden decrease in the airflow speed, the dust migration speed in the area behind the roadheader is slowed down; a large number of dust particles are carried by the airflow into the stable area.As the dust flows back, the remaining dust is carried to the outlet of the air duct.As a result, the area about 5 m behind the roadheader and the area near the outlet of the air duct contain high dust concentration, and the dust concentration near the outlet of the air duct increases with the increase of the ventilation speed when the ventilation speed is more than 16 m/s due to the strong entrainment effect.