Methods for preparing imidodisulfuryl fluoride and alkali metal salt thereof

The invention belongs to the technical field of fluorochemical industry, and particularly relates to methods for preparing imidodisulfuryl fluoride and alkali metal salt thereof. The method for preparing imidodisulfuryl fluoride comprises the steps of mixing imidodisulfuryl chloride with ether-nHF complex, conducting stirring reaction for 1-20 h at 0-100 DEG C, and conducting reduced pressure distillation after reaction to obtain imidodisulfuryl fluoride. The method for preparing alkali metal salt of imidodisulfuryl fluoride comprises the step of mixing imidodisulfuryl fluoride with MF for reaction under ball milling to obtain a crude product of alkali metal salt of imidodisulfuryl fluoride, wherein reaction temperature is 10-30 DEG C, reaction time is 2-20 h, and M is Li, Ma or K. The technical scheme is safe, efficient and suitable for industrial production.