The invention discloses a method for preparing cyclohexanone and cyclohexanol by decomposition of a cyclohexane oxidation liquid. The method comprises the following steps: a cyclohexane oxidation liquid is subjected to a homogeneous decomposition reaction in the presence of an oil-soluble catalyst isooctyl chromate at the reaction temperature of 100-160 DEG C at the pressure of 0.3-0.8 Mpa for 1.0-5 h; after the decomposition reaction, the decomposition liquor is cooled and then washed with alkali lye, followed by standing and alkali separation; then, an organic phase and an inorganic phase are obtained; and the organic phase is separated and refined so as to obtain cyclohexanone and cyclohexanol. By using the oil-soluble catalyst isooctyl chromate, the traditional thinking of using aqueous alkali for heterogeneous decomposition is broken through. By changing the catalytic system and reaction condition, cyclohexyl hydroperoxide decomposition rate reaches 99.8% and above, yield of cyclohexanone and cyclohexanol obtained after the decomposition is 98% and above, and ketone-to-alcohol ratio is 1.3:1 and above and far higher than the ratio of 1:1 in traditional basic decomposition. As the cyclohexyl hydroperoxide decomposition reaction needn't be carried out under the alkaline condition, consumption of alkali is also greatly reduced.