The invention belongs to the technical field of butanone preparation, and particularly relates to a method for preparing butanone through oxidative decarboxylation of levulinic acid. The method comprises steps of adding a 1-butyl-3-methylimidazole chlorine salt ionic liquid and nanometer copper oxide into levulinic acid, regulating the pH value to be 3.5-9, and reacting for 1.5-2.5 hours at 280-320 DEG C. According to the method, butanone is synthesized through decarboxylation of levulinic acid, so that the crisis caused by shortage of petrifaction resource is relieved, and environment contamination is lightened, therefore, the method has a good application prospect and great practical significance.