The reaction mechanisms of C-S borylation of aryl sulfides catalyzed by the 1,4-benzoquinone (BQ), were investigated by employing M06-2X-D3/ma-def2SVP method and basis set. In this study, the SMD model was taken to simulate the solvent effect of 1,4-dioxane. Also, TD-DFT calculations of BQ and methyl(p-tolyl)sulfane were performed in SMD solvent model. The computational results indicated that BQ and methyl(p-tolyl)sulfane, serving as a photo-catalyst, would be excited under blue LED of 450 nm, aligning well with experimental observations. Additionally, the role of 3O2 was investigated, revealing that it could be activated to 1O2 from the released energy of 1[BQ+methyl(p-tolyl)sulfane]* or 3[BQ+ methyl(p-tolyl)sulfane]*→BQ+ methyl(p-tolyl)sulfane process. Then 1O2, bis(pinacolato)diboron, and methyl(p-tolyl)sulfane would through a series of reactions to yield the final product P. The Gibbs free energy surface show that path a2-2 is optimal and this path has less steps and lower energy barrier. The electron spin density isosurface graphs were employed to analyze structures and elucidate the single electron distribution. These computational results offer valuable insights into the studied interactions and related processes and shed light on the mechanisms governing C–S borylation from aryl sulfides and b2pin2 catalyzed by BQ and methyl(p-tolyl)sulfane.