Abstract: A series of Fe₂O₃/Ni₂O₃/Al₂O₃ catalysts were prepared by the method of impregnation and precipitation with Al₂O₃ as supporter. The catalysts were characterized by thermogravimetry，X-ray diffraction（XRD），scanning electron microscope （ESEM）.Results indicated the optimal calcined temperature was 460 ℃.The effects of the different mass ratios of Ni₂O₃/Al₂O₃，Fe₂O₃/Ni₂O₃/Al₂O₃ and NaClO/indigo wastewater，reaction temperature，and pH on the decomposition rate of dyeing indigo wastewater were investigated by using NaClO as oxidant.Results showed that the highly COD conversion of indigo wastewater could reach up to 95.3% at atmosphere pressure under such reaction conditions：m（Ni₂O₃）/m（Al₂O₃）=0.3，m（Fe₂O₃）/m（Ni₂O₃）=0.04，m（NaClO）∶m（indigo wastewater）=1∶11，pH=7， reaction temperature was 20 ℃，and reaction time was 2 h.

Key words: impregnated precipitation, Fe₂O₃/Ni₂O₃/Al₂O₃ catalyst；NaClO；active oxygen；indigo wastewater