Abstract: According to the high gas steeply inclined middle coal seam geological condition in the 1155 fully mechanized caving face,combined with the coal seam gas based parameters,it is concluded that the coal seam gas can be extracted;using the theoretical analysis and field measurement methods,the gas extraction methods and the gas extraction design parameters are determined.The field gas extraction datum show that the max residual desorption gas quantity of the Cu2 coal seam is 4.05m³/t,the average gas extraction rate is 47.1%,the gas concentration in the return air is no more than 1%,the effect of gas extraction reach the standards.The gas extraction in t the 1155 fully mechanized caving face can ensure the safe and efficient production,and can be used as references for popularization and application in other fields of similar condition.