We report a Se-S dynamic exchange reaction as a methodology for highly efficient S-S bond cleavage. In this study, a Na2Se-disulfide dynamic exchange reaction has been demonstrated for the first time and the strategy has been employed in the preparation of benzothiazole derivatives, demonstrating highly efficient S-S bond cleavage, lowered dosage of the S-S bond cleaving reagent, good tolerance toward various substituents and excellent yields. It is envisaged that the concept of metal selenide-disulfide dynamic interchange reaction is a general avenue for synthesizing sulfur-containing heterocycles.