Drilling and blanking integrated and heat injection coordinated enhancing method for extracting coal seam gas

The invention provides a drilling and blanking integrated and heat injection coordinated enhancing method for extracting coal seam gas. The method is applied to the treatment of gas in a microporosit, low-penetration and high-absorbing coal seam area. The method is that gas extracting holes are constructed at a certain distance to the surrounding of a preset drilling and blanking drilling hole; gas is extracted after the holes are sealed; a drilling and blanking integrated drill bit is utilized for constructing a drilling and blanking drilling hole and sealing the hole; the change on the concentration in the gas extracting holes is monitored on real time; when the concentration in the holes is less than 30%, an opening of each drilling and blanking drilling hole is opened, high temperature steam fills inside through a steam generator, and then the drilling and blanking drilling hole is sealed; the pressure release space and the coal exposing area can be increased by constructing the drilling and blanking drilling hole, the stress of the coal is removed, and the breathing performance of a coal seam is improved; in addition, the high temperature steam fills inside to prompt the desorption of the coal gas, the cracks surrounding the drilling hole are expanded, and therefore, gas flowing channels are further increased, and as a result, the efficient coal seam gas extracting is achieved.