Abstract: The coking wastewater which meets the discharge standard still contains a small quantity of organic compounds. A self-made cylindrical bubbling reactor was established by coupling the O3/H2O2 oxidation process was used to remove these residual compounds to realize industrial water reuse cycle. The effects of O3 concentration, H2O2 dosage, pH and free radical inhibitor were investigated. The results showed that when the environmental temperature, pH, O3 concentration and H2O2 dosage were 25℃, 7.0, 11.01 mg/L and 1.0 mmol/L respectively, the removal ratios of COD and UV254 were 78.1% and 83.7% for O3/H2O2 oxidation process, whereas the removal ratios were just 63.8% and 79.6% for O3 alone. The reaction process was affected by the acidity significantly. Tribenzyl amine (TBA) was added in the reaction liquid as a ·OH free radical inhibitor to confirm the oxidation mechanism. The aromatics removal was approximate during the first 15 min for the system with and without TBA. This result indicated that O3 was the dominating oxidant. 4 g/L TBA could inhibit the production of ·OH which meant nearly 20% oxidation was accomplished by ·OH. It was concluded that the complex components contained in the wastewater were oxidized according to the unsaturation of organic compounds and the redox potential of the oxidants.