The invention relates to a 2-arylsulfonyl-2, 2-difluorodiazoethane compound, a preparation method and application thereof. The preparation method of the 2-arylsulfonyl-2, 2-difluorodiazoethane compound includes: dissolving 2, 2-difluoro-2-aryl sulfonyl ethylamine hydrochloride in a mixed solvent of an organic solvent and water, adding nitrite, carrying out stirring at room temperature for completereaction, and then conducting washing, extraction, separation and column chromatography purification to obtain the yellow liquid 2-arylsulfonyl-2, 2-difluorodiazoethane. The obtained target compoundis a diazo compound containing sulfonyl difluoromethyl, can be subjected to [3+2] cycloaddition reaction with alkyne so as to synthesize a pyrazole compound containing difluoromethyl. The difluorodiazoethane compound provided by the invention has the characteristics of convenient preparation, simple use and mild reaction conditions, and the invention provides an effective method for synthesis of compounds containing difluoromethyl.