The macrokinetics of Hg-0 oxidation by a vaporized multicomponent oxidant (MO) that was composed of Fenton reagent, peroxyacetic acid (PAA), and NaCl was evaluated. The effects of various influencing factors on Hg-0 oxidation were investigated, such as MO constitutions, MO pH, reaction temperature, and coexistence gases. The experimental results indicated that the ideal additives for Hg-0 oxidation were NaBr, NaCl, NaClO, and PAA, whereas NaCl was more economical; the increasing pH of MO was unfavorable to Hg-0 oxidation; SO2 and NO in the simulated flue gas exhibited a reverse effect on Hg-0 oxidation, depending on their concentrations. The Hg-0 oxidation conformed to a pseudo-first-order kinetics pattern under the experimental conditions. And the rate constants determined at 343-423 K fit the Arrhenius equation well, yielding an apparent activation energy of 14.3 kJ/mol. Meanwhile, the mechanism of Hg-0 oxidation was also deduced.