Tectonically deformed coal (TDC) is widely distributed in major coalbed methane (CBM) producing areas in China, and its fissure-like pore structure is a key factor regulating methane adsorption-desorption behavior. To clarify the coupling mechanism of fissure width, tectonic deformation degree, and methane adsorption, three brittle TDC samples with different deformation intensities (Tunlan: weakly deformed, TL; Malan: moderately deformed, ML; Jining: strongly deformed, JN) from the Xishan Coalfi