Triethylamine hydrogen trifluoride, as a fluorinating reagent, has incomparable superiority such as HF; It is a near-neutral substance and is non-corrosive to borosilicate glass containers; It can be used for the substitution reaction of carbohydrate derivatives and aromatic Chemicalbook hydrocarbon derivatives, and can also be used for addition reaction and desiliconization reaction of olefins; In recent years, triethylamine hydrogen trifluoride has been widely used as a fluorine source in the field of electrochemical fluorination of organic compounds.