The invention relates to a method for preparing cyclohexane by a benzene one-pot process. The method comprises the following steps of putting benzene, hydroxylammonium salts, catalysts and solvents into an autoclave; performing replacement through N2 introduction; then, raising the temperature to 70 to 90 DEG C; performing a reaction for 2 to 3 hours; then, raising the temperature to 110 to 130 DEG C; introducing the hydrogen gas to reach the pressure of 2.5 to 3.5MPa, maintaining the pressure; after the reaction for 2 to 3 hours, stopping the hydrogen gas introduction, and stopping reaction; after the autoclave is cooled to the room temperature, neutralizing reaction liquid, then, performing extraction separation and obtaining a product of cyclohexane, wherein the catalysts are vanadium catalysts and ruthenium catalysts. The cyclohexane is prepared by using the benzene as raw materials through a one-pot process; the complicated reaction steps are omitted; the synthesis process is simpler and more convenient; the energy loss due to multi-step reaction is reduced. The method provided by the invention has the advantages that through the process route, the environment pollution and the equipment damage caused by waste acid such as nitric acid and hydrochloric acid can be reduced; better green and environment-friendly effects are achieved.