Gas control of fully mechanized coal face in Longfeng Mine was taken as the research object, the problem of the gas exceeding limit in the working face, upper corner and return air lane of Longfeng coal mine was analyzed. The important reason that the effect of No. 4 gas causing the increase of gas concentration was obtained. At the same time, the air volume of the working face and the ventilator were designed. The gas concentration in the working face, the upper corner and the return air lane was drained by the mining, positive pressure dilution and the total row negative pressure method. From the field test, the total row negative pressure method exerted a great advantage in the technical and economic aspects, which can effectively improve the effect of the gas treatment in the fully mechanized face.