Add anhydrous tetrahydrofuran (its mass ratio to maleic anhydride is 1.5:1), cat-1 (0.05 mole), maleic anhydride (1 mole), and o-phthalaldehyde (1.5 mole) to the reactor. After adding triethylamine (5 moles), adjust the temperature below -40°C. Silicon tetrachloride (4 moles) was added dropwise to the reaction system and the reaction was placed at -40 °C for 4 h. The mixture was heated to reflux for 20 h. After the end of the reaction, concentrating the solution to a certain concentration with diatomaceous earth filtration. A light yellow solid, namely 2,3-Naphthalenedicarboxylic Anhydride, is obtained by precipitation, filtration, recrystallization and drying. Its yield reaches 88%.