Potassium salt of 1-methylamino-1-thio-2-nitroethylene was synthesized from nitromethane, methyl isothiocyanate in the presence of macronano-K2CO3 and then reacted with dimethyl sulfate in water to give 1-methylamino-1-methylthio-2-nitroethylene. The overall yield was 86%. The effects of molar ratio of raw material, reaction temperature and reaction time on conversion rate of methyl isothiocyanate were investigated. The target products were characterized by means of FTIR and 1HNMR.