An efficient method for the preparation of 1,3,4-thiadiazine derivatives has been reported. With 2,5-dihydroxy1,4-dithiane and alpha-chloroindole containing different substituents, 13 compounds were synthesized. The yields of the compounds were above 82% except (E)-4-phenyl2-stY1)71-5,6-dilwdre-411-1,3,4-illiadiazin-5-01 (31n)- flirtbemiere, the ProPosed reaction mechanism was discussed. The developed method features simple operation, mild reaction condition, environmentally friendly, high yield and a broad range of substrate applicability. It provides a new way for the synthesis of 1,3,4-thiadiazine derivatives.