Abstract: This paper introduced the theory of gas drainage in high level drainage roadway, the reasonable gas drainage parameters in high level drainage roadway was determined combined with site experience, including negative pressure, drainage horizon and horizontal distances. The results showed that the negative pressure either too high or too low is not conducive to gas drainage in high level drainage roadway, the appropriate range of it is from 12 kPa to 15 kPa.According to the field observation, the gas drainage effect is good when the distance from high level drainage roadway to the roof of the coal seam is between 49 m to 54 m.Based on the "O" ring theory, the horizontal distance is determined as 35.1 m.In view of the abnormal phenomenon of gas drainage during the drainage process in high level drainage roadway, the reason of it was analyzed, and the rationality of the selected parameters is proved indirectly.