The invention discloses a method for synthesizing 1,4-naphthoquinone by catalyzing an ionic liquid. The method is characterized in that 130 mass parts of naphthalene, 1.3-13 mass parts of an ionic liquid, 650 to 1,300 mass parts of acetic acid, 130 mass parts of a booster solvent are added into a reactor, the temperature is increased to 50 to 100 DEG C during stirring, 1,135 to 3,400 mass parts of a hydrogen peroxide water solution with the mass concentration of 30 percent is completely dripped within 1.5 to 2.5 hours, after dripping, heat-insulating reaction lasts for 2 to 5 hours, then filtering is performed, insoluble precipitates are eliminated, a filter liquor is extracted by a resolvent cyclohexane, organic phases are taken, after water washing and drying, reduced pressure distillation is performed, and remnants are the prepared 1,4-naphthoquinone. According to the invention, the method provided by the invention has the characteristics of environment friendless, simplicity and convenience in operation, fast reaction speed and the like, the product cost is low, the commercial effect is excellent, and the practicability is strong.