NOVELTY - Synthesizing furoxan compounds (II), comprises reacting alpha -nitro oxime compounds (I) and substituted sulfonyl chloride compounds (III) in a solvent at -10 degrees C to -50 degrees C, adding an alkali, and continuously stirring, and separating, and purifying, where the alkali is an organic alkali or an inorganic alkali, and the organic alkali is 1-6C aliphatic organic amine, diisopropylethyl amine or triethylenediamine hexahydrate, and the inorganic alkali is hydroxide or carbonate of an alkali metal or alkaline-earth metal, and the solvent is e.g. toluene, mesitylene, dichloromethane or acetone.    USE - The method is useful of synthesizing furoxan compounds (claimed).    ADVANTAGE - The method has mild reaction and high yield (more than 95%); can prepare varieties of different substituents of asymmetric furoxan compounds by using substituted sulfonyl chloride compounds as raw material in a cost-effective manner; can be carried out in short period (20 minutes); and is environmentally friendly.    DETAILED DESCRIPTION - Synthesizing furoxan compounds of formula (II), comprises taking alpha -nitro oxime compounds of formula (I) and substituted sulfonyl chloride compounds of formula (III), and then adding a solvent, placing in a reaction container, reacting at -10 degrees C to -50 degrees C under stirring condition, adding an alkali, and continuously stirring, and separating, and purifying, where the molar concentration of (I) is 0.033-0.2 mol/l, and the molar ratio of (I) and (III), is 1:1.1-1:2, and the alkali is an organic alkali or an inorganic alkali, and the organic alkali is 1-6C aliphatic organic amine, diisopropylethyl amine or triethylenediamine hexahydrate, and the inorganic alkali is hydroxide or carbonate of an alkali metal or alkaline-earth metal, and the solvent is toluene, mesitylene, dichloromethane, chloroform, tetrahydrofuran, ether, acetonitrile, ethanol, methanol, 1,4-dioxane alkoxy, chlorobenzene or acetone.    R1 = aryl, heteroaryl, alkyl or ester;    R2 = hydrogen, aryl, heteroarylalkyl, ester or cyano; and    R3 = methyl, phenyl, p-tolyl or p-nitrophenyl.