The invention discloses a bacillus licheniformis purification method. The method comprises the following steps: (1) taking a bacillus licheniformis strain, inoculating the bacillus licheniformis strain, preparing uniform bacterial suspension and preserving the bacterial suspension at 5-7 DEG C for later use; (2) adding a first culture medium to a No.2 conical flask and carrying out shaking culture, thus obtaining a strain; (3) taking a second culture medium, adding distilled water to the culture medium, boiling the culture medium on an electric furnace for 5-10min, cooling the second culture medium to room temperature and solidifying the second culture medium for later use; (4) melting the second culture medium, coating the second culture medium on a plate, then carrying out streak culture on the strain on the plate and separating and purifying bacillus licheniformis; and (5) cultivating separated and purified bacillus licheniformis. The method has the beneficial effects that the success rate of purification is increased by further separating and purifying the bacillus licheniformis strain sold on the market after culturing, enlarging and adapting the bacillus licheniformis strain, so that the purified bacillus licheniformis strain fully shows better growth performance.