Abstract: In the process of coal dust suppression, it′s important to grasp the laws of coal dust migration，that will improve the efficiency of dust suppression. With the help of FLUENT software, we simulated the dust migration in roadway under different wind speeds, obtained the dust and size distribution, and do the corresponding test on site. Results showed that: after coal dust production, migration mainly occurs near the coal wall, concentration is higher at here, and the big size particle settles down significantly, with the advancing of wind, the small size particle diffuses obviously along the working section and coal dust concentration along the working face is gradually reduced.