In this article, a complex oxidant (CO) composed of NaClO and NaClO2 was employed to remove arsenic from flue gas. Experiments were conducted to evaluate the effects of several influencing parameters on arsenic removal efficiency in a bench-scale reactor, such as molar ratio of NaClO to NaClO2, solution pH, solution temperature and various flue gas components including O-2, SO2, NO, CO2. The results indicated that the arsenic removal efficiency could reach 100%, under the optimum experimental conditions, in which molar ratio of NaClO to NaClO2 was 1.0, solution pH was 5.5-6.0, solution temperature was 50. Besides, it was also observed that O-2 and CO2 did not affect the removal of arsenic while both SO2 and NO concentrations in flue gas could significantly inhibit the removal of arsenic. Furthermore, the final reaction products in the solution were analyzed by high-performance liquid chromatography coupled with a hydride-generation atomic fluorescence spectrometer (HPLC-HG-AFS), the reaction mechanism and pathways of arsenic removal using complex absorbent were proposed. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.