The invention discloses a method for preparing cycloxylidin, which belongs to the technical field of pesticides preparation. The method comprises the following steps: under nitrogen protection, N-nitroiminoimidazolidine and an organic solvent are added in a reactor, then sodium hydride is added in batches, and the material is heated to the temperature of 50-60 DEG C, chloropropylene oxide is added drop by drop in the reactor, after the reaction product is cooled, chloroform is added, and the product is filtered by diatomite, then evaporative crystallization is carried out, and the crystals can be precipitated, vacuum distillation is carried out on a processed filtrate to obtain a light yellow dense solid, then heat chloroform is used for extraction, and finally heat ethanol or acetone is used for recrystallization to obtain cycloxylidin: 1-(2,3-glycidyl)-N-nitroimidazoline-2-ylamine, wherein the yield is about 83%. The method has the advantages of short reaction time, high yield and green environmental protection, and is more suitable for large-scale industrial production.