Abstract: In order to ascertain the treatment effect and influencing factors of heterogeneous catalytic ozonation process for treatment of high-salt wastewater from coal chemical industry,MgO-Al2O3 catalyst was prepared by using alumina powder as raw material,and characterized by scanning electron microscopy and specific surface area instrument.COD removal rate was used as an indicator to study the effect of ozone oxidation alone and MgO-Al2O3 as catalyst for the oxidation of COD,and the effects of catalyst and ozone dosages for catalytic ozonation were discussed.The results show that the surface of MgO-Al2O3 catalyst is not flat,contains metal oxide MgO,and has a large specific surface area,reaching 153.5 m2/g.The COD removals by ozone oxidation and catalytic ozonation reach 45% and 61%,respectively,and the latter has a better COD removal effect.The dosages of catalyst and ozone all affect the treatment effect of catalytic ozonation,increasing the dosages of them can increase the COD removal effect.However,after the excess,the removal effect will not be significantly improved.The optimum dosages of catalyst and ozone in the experiment are 300 g/L and 260 mg/(L·h),respectively.