In recent years, advanced oxidation technology (SR-AOPs) based on sulfate radical (SO₄^·-) is developing rapidly.The catalysts and related mechanisms for the stable and efficient generation of SO₄^·- have been focused by researcher.In this work, the heterogeneous silicon-based highly dispersed cobalt oxide (CoNSi) was synthesized through ammonia modified adsorption roasting method.Moreover, CoNSi was used to activate the industrial by-product sulfite (S(IV)) to achieve the purpose of “waste control by waste”.The effect of pH value, CoNSi and sodium sulfite (Na₂SO₃) dosages, AO7 concentration, and oxygen on the degradation of AO7 was investigated separately.Furthermore, the effect of sulfite concentration and AO7 concentration on the initial rate of AO7 degradation reaction was analyzed.The results indicated that the degradation efficiency of AO7 in aerobic environment could reach 79.4% under the conditions of initial pH of 9.0, CoNSi of 0.25 g/L, Na₂SO₃ of 1.0 mM and AO7 of 7 mg/L.Moreover, the stability of CoNSi activated sulfites was demonstrated by sequencing experiments.Radical trapping experiments elucidated that SO₄^·- is the main active species in this system.