The　first　three-component　cyclization　reaction　of　benzo[c][1,2]dithiol-3-ones　based　on　S-S　bond　cleavage　is　disclosed　herein.　A　range　of　2,3-dihydrobenzothiazin-4-ones　were　achieved　in　decent　yields　under　mild　conditions.　The　current　synthesis　route　features　advantages　such　as　simple　operation,　readily　available　raw　materials,　transition-metal-free　conditions,　no　protection　of　inert　gases,　good　yields,　excellent　functional　group　compatibility　and　accessible　scalability.　The　first　three-component　cyclization　reaction　of　benzo[c][1,2]dithiol-3-ones　based　on　S-S　bond　cleavage　is　disclosed　herein.