Method for treating organic wastewater

The invention relates to a method for treating organic wastewater, which comprises the following steps: (I) adjusting the pH value of organic wastewater; (II) performing a Fenton reaction on the organic wastewater; (III) performing a coagulating sedimentation reaction; (IV) filtering the organic wastewater treated by step (III); and (V) adsorbing the organic wastewater treated by step (IV) by use of activated carbon, wherein in the process of step (II), ozone is supplied to the organic wastewater for the Fenton reaction. In the method provided by the invention, the hydrogen peroxide in the original Fenton reaction is replaced by ozone; under the catalysis of ferrous ions, the number of hydroxyls generated by ozone is about 3 times that of the hydroxyl generated by the same amount of hydrogen peroxide, thus the oxidation capacity of ozone is stronger, and the efficiency of the method is higher; after the treatment by the method, the removal rate of COD in the organic wastewater can reach 93%; and the treated o