Abstract: Aiming at the problems of soft and low permeability coal seam and difficulty of gas drainage at 1307 working face of Zhaozhuang Coal Mine, we try to use the method of gas injection and replacement to promote the drainage in the hole drilling of floor drainage roadway, and arrange the gas injection holes and drainage holes reasonably and test the effect of gas injection; the results show that the experimental study of gas injection and promoting drainage is feasible, which improves the effect of coal seam gas drainage and so as to ensure the safe and efficient mining of 1307 working face.