Abstract: Cu -based catalyst prepared by impregnation method was used in the catalytic ozonationprocess. The influences of operating parameters on the treatment effect of secondary effluent in the in-dustrial park was discussed. The three-dimensional emission electron microscope ( 3D-EEM) was usedto analyze the variation characteristics of water quality. The result showed that when the reaction time ofozonation alone was 60 min,the removal rates of COD and total nitrogen ( TN) were 29.7% and 5.3%,respectively,and SUVA254 indicating the degree of aromatization decreased rapidly from 2.7 L/( mg·m) to 1.0 L/( mg·m) . When the dosage of Cu-based catalyst was 100 g /L and the reaction time was60 min,the removal rates of COD and TN reached to 84.7% and 19.8%,respectively,and SUVA254 wasstable at 0.9 L/( mg·m) . The removal rate of total fluorescence intensity reached to 89.5% after cata-lytic ozonation reaction for 20 min. Close-