The efficient conversion of CO₂ to high value-added chemicals in water with cheap and non-toxic catalysts is a very attractive topic in green chemistry. In this work, the transformation of CO₂ and 2-aminobenzonitriles to quinazoline-2,4(1H,3H)-diones in water promoted by choline hydroxide has been studied. The effect of temperature, pressure, reaction time, and amount of catalyst on the reaction were investigated and the reaction conditions were optimized. It was demonstrated that choline hydroxide showed supernormal catalytic activity to promote this reaction as a biodegradable, environmentally friendly, green and cheap material showed supernormal catalytic activity to promote this reaction. Furthermore, the reaction mechanism was discussed.