Abstract: Complex iron wet oxidative desulfurization process has high absorption efficiency and flexible operability. Most desulfurizers can be regenerated, economic and environmental friendly. It is one of the hotspots in desulfurization research field. The oxidative regeneration system of EDTA-Fe(Ⅱ) solution was studied in the gas-liquid diffusion reactor. The reaction kinetics of complex iron was studied by electrochemical method and the theoretical model of concentration distribution of complex ferrous iron was established and tested during the regeneration process. The results showed that the reaction order of oxygen volume fraction, EDTA-Fe(Ⅱ) concentration and hydrogen ion concentration were 0.8, 0.902 and -0.152, respectively, and the apparent activation energy was 14.24 kJ/mol. The calculation results of the model agreed well with the measured data, it could better predict the change of complex ferrous iron concentration at different time in the regeneration process. The model has some theoretical significance for guiding the design of regeneration reactor, the volume flow of air blast, the addition amount of complexing agent and the addition position in desulfurization process.