The invention discloses a method for preparing cyclohexanone by oxidizing cyclohexanol at the normal temperature by virtue of hydrogen peroxide. The method comprises the following steps: (1) adding a certain amount of cyclohexanol into a nonpolar or weak-polar organic solvent for dissolving in advance; (2) dissolving a small amount of sodium bromide and catalysts into a hydrogen peroxide water solution, and controlling the solution at a certain pH value; (3) adding the two materials into a reaction device, controlling the hydrogen peroxide water solution to be acidic, and stirring to react at room temperature for a certain period of time; (4) adding a very small amount of catalyst into the acidic hydrogen peroxide water solution, so as to shorten reaction time in the reaction process; (5) after the reaction, standing to react to stratify the materials, extracting an organic phase solution, and carrying out reduced pressure rectification, so as to obtain cyclohexanone. By utilizing the technical method provided by the invention, the temperature of oxidation reaction of hydrogen peroxide is greatly decreased, a large number of energy sources can be saved, and the safety production is guaranteed; and meanwhile, the reaction yield is high, the product is easy to separate, and catalysts and the like can be recycled.