Abstract: In order to obtain the best process parameters of ozone catalytic oxidation,the impact of ozone ventilation,ozone concentrationand catalyst dosage on COD removal was studied by using single factor and orthogonal test method in 1 t/h ozone catalytic oxidation device-and the primary and secondary order of process conditions and the best process parameters were determined.Finally,the best process pa-rameters were tested continuously for 80 hours,and the removal effect of COD under the best process parameters was further investigated. Itis concluded that the three process conditions(i.e. ozone concentration,ozone ventilation capacity and catalyst dosage) have a great influ-ence on COD removal rate.Through single factor experiment,it is found that with the increase of ozone ventilation,ozone and catalyst dos-age,the COD removal rate will increase under the same conditions,but the treatment cost will increase. Considering COD removal rate andozone ventilation cost,the ozone ventilation rate is 1.5 m~3/h≤ozone ventilation rate≤2.5 m~3/h;the ozone concentration is 150 mg/L≤ozone concentration≤250 mg/L;the catalyst dosage is selected as 20 kg/t≤catalyst dosage≤30 kg/t.Through the orthogonal experiment,it is found that the primary and secondary order of the influence of three ozone oxidation conditions on COD removal rate is ozone concen-tration > ventilation > catalyst dosage,which confirms the above single factor test results. The best process parameters are obtained:ozoneventilation 2.0 m~3/h,ozone concentration 250 mg/L,catalyst dosage 30 kg/t.Finally,1 t/h ozonation device was used to carry out continu-ous ozonation test on the wastewater after phenol removal and ammonia evaporation for 80 h under the optimal process parameters and theremoval rate of COD was stable at about 43.5%,and the biodegradability(B/C) after reaction was stable above 0.4,which reduced the loadand difficulty of subsequent biochemical treatment. It is proved that the ozone oxidation process has a good practical application effect.