Abstract: Based on the actual situation of 9101 working surface of a mine in Shanxi Province, we use Fluent simulation software to study the effect of different drainage negative pressure of high level suction roadway on gas migration laws of gob. The results show that: gob area shows a tendency of gradually decreasing in high gas area and gradually increasing in low gas area under different drainage negative pressure in high level suction roadway, the gas concentration in the turn air in the goaf is lower than that in the wind side, and the closer the distance to the working face, the more obvious the influence of gas extraction; with the increase of drainage negative pressure in high level suction roadway, the mixing amount of the high suction roadway and the amount of gas extraction are gradually increasing. When the negative pressure is over 12 kPa, the growth rate of extraction gas is obviously decreased; the concentration of extraction gas increases first and then decreases, there is a peak of 14.25% when the negative pressure is 12 kPa. Comprehensively considering the change of gas purity and gas concentration in high extraction roadway, it is reasonable to confirm that the negative pressure of the 9101 working face is 12 kPa. The gas concentration in the goaf is basically consistent with the simulated value, the error is within the allowable error range of the projec.