Abstract: The equilibrium potentials of H₂O/O₂ and Fe³⁺/Fe²⁺are much greater than those of Cu²⁺/Cu in acid solution, by which oxygen can be reduced or oxidize iron(Ⅱ)to iron(Ⅲ)on cathode electrode.Then follows the reduction of iron(Ⅲ)on the same electrode when oxygen is used to be the oxidant and cathode and anode chamber are separated via anion exchange membrane.This process makes single membrane and low potential dissolution possible, and also holds advantages of less solution and lower electricity consumption.The technical conditions selected are as follows: tank voltage is 0.32~0.55 V, temperature 60 ℃, electrodes gap 3 cm, H₂SO₄ and FeSO₄ concentrations in cathode chamber is 35 g/L and 76 g/L respectively, H₂SO₄ concentration in anode chamber is 25 g/L with enough oxygen supply.Ion concentration is controlled to crystallization-free.Current density and current efficiency reach 300~500 A/m² and 98.7 % respectively.