Method for detecting igneous rock small structure in underground coal seam of coal mine

The invention discloses a method for detecting a small igneous rock structure in an underground coal seam of a coal mine, which is suitable for detecting the small igneous rock structure in the coal seam near an igneous rock invading body and provides powerful support for solving the problems of drill jamming, hole spraying and the like caused by the small igneous rock structure in a coal mine gas treatment process. By assuming the diameter of the igneous rock small structure in the coal seam, directional drilling is conducted on the coal seam through the directional drilling technology, working information of a drill bit is obtained in real time, the contact point position of the drill bit and the igneous rock is determined, and therefore position information of the igneous rock small structure in the coal seam is gradually determined. The problem that the position and the shape of the igneous rock small structure cannot be accurately detected under existing conditions is solved. And finally obtaining the po