In recent years, the sulfate radicals (SO4?-) based advanced oxidation technology（SR-AOPs） have developed rapidly. The catalysts and related mechanisms for the stable and efficient generation of SO4?- have been focused by researcher. In this work, a heterogeneous catalyst of highly dispersed cobalt oxides based silicon (CoNSi) was synthesized through an adsorption-combustion process modified by ammonia. 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.