| In order to explore the degradation regularity of the thiophene organic sulfur compounds in coal. Through searching transition states, it proposes two reaction paths using the density functional theory. It gets that the difficulty of each path is different, the more favourable reaction path of thiophene degradation is Path 1 basing on atomic charges of every species, thermodynamics and dynamics parameters of the reaction paths and the analyzing the potential energy profiles of thiophene degradation. Firstly, H9 transfers to S5, then H8 transfers from C3 to C4 with C4-S5 bond fracturing, H6 transfers to S5. Finally, with the H7 transfering from C2 to C1, H2S deviates from the original structure and diacetylene formats. The changing rule of the different degradation paths of the thiophene sulfur model compounds in coal were studied using the density functional theory, it can help to understand the removal mechanism of the thiophenic sulfur in coal and provide theoretical guidance for experiments of the thiophene organic sulfur removal in coal and industrial process.