The invention discloses a multi-stage permeability increasing method for a coal body containing gas. The multi-stage permeability increasing method for the coal body containing gas comprises the steps that firstly, the geological condition of the occurrence area of a coal seam, the metamorphism degree of coal, the type of the coal and gas parameters are determined; secondly, different schemes are adopted for achieving first-stage permeability increasing of the coal body containing gas according to the fact whether the coal seam is located in a fault or a fold part or not, the permeability increasing effect is checked, and if the permeability increasing effect reaches a preset effect, the scheme adopted for first-stage permeability increasing is used for permeability increasing of the whole coal seam; if the permeability increasing effect does not reach the preset effect, second-stage acidification permeability increasing is conducted on the coal body containing gas based on first-stage permeability increasing; and finally, after second-stage acidification permeability increasing is completed, gas extraction is conducted on the coal body containing gas. According to the multi-stage permeability increasing method for the coal body containing gas, different permeability increasing schemes are established according to the geological conditions of different occurrence areas of coal seams, and thus the multi-stage permeability increasing method is extremely targeted; and meanwhile, by adoption of multi-stage permeability increasing, the permeability of the coal seams is greatly improved, and the gas extraction rate is increased.