The specific synthesis method of Tetrafluoroterephthalonitrile is as follows: Potassium fluoride was dired at 500°C and then pulverized. Dimethylformamide was desiccated over potassium hydroxide pellets and then distilled under nitrogen. The water content thereof was determined in dehydrated methanol by the Karl-Fischer method to be 0.02% by weight. A reactor having a reflux condenser, within which the atmosphere was displaced with nitrogen gas, was charged with 1.330 grams of tetrachloroterephthalonitrile, 1.743 grams of dry potassium fluoride, and 10 milliliters of said dimethylformamide. After that, the mixture was heated to 130°C with simultaneous agitation and allowed to undergo a reaction for five hours. After that, the contents of the reactor were poured into ice water, and a saturated aqueous solution of sodium chloride was added.Consequently, the reaction product separated and floated to the surface. The floating phase was separated by filtration, washed with water, and dried. The yield of the product was calculated to be 81.0%.