Underground coalbed pulsed detonation wave directional cracking anti-reflection method

An underground coalbed pulsed detonation wave directional cracking anti-reflection method is suitable for regional gas control of high-gas low-permeability coalbeds and comprises the following steps: firstly, respectively implementing pulsed detonation drilling and pulsed detonation guiding drilling from a coal road to a coalbed, then pushing a positive electrode connected to the positive output terminal of an explosion-proof high-voltage electro-pulse generator to the bottom of a pulsed detonation drill hole, pushing a negative electrode connected to the negative output terminal of the explosion-proof high-voltage electro-pulse generator to the bottom of a pulsed detonation guiding drill hole, and after finish of the electro-pulse detonation cracking implementation, connecting the pulsed detonation drill hole and the pulsed detonation guiding drill hole to an exhausting and mining pipeline for gas extraction. According to the method, the instant high-energy cracking coal provided by electro-pulse detonation waves is utilized, and a crack network is formed in the coal between the pulsed detonation drill hole and the pulsed detonation guiding drill hole, so that the gas permeability coefficient of the coal can be improved by 200-400 times, the effective influence scope of single-drilling gas extraction can be improved by 3-4 times, the drilling gas extraction quantity can be increased by 3-8 times, and the coalbed gas pre-extraction time can be effectively shortened.