Abstract: The graphite felts modified by multiple oxidation method apply to Zn/Fe flow battery for the first time. After the surface of graphite felts has been treated by KMnO₄ and mixed acid (V sulfuric acid:V phosphoric acid = 9:1), the oxidized graphite felts are treated with H₂O₂. The functional structure and surface morphology of the treated graphite felts are analyzed by IR and SEM. And graphite felts treated at different temperatures have effects on the electrochemical performance. The result shows that the graphite felts treated at 50 ℃ as electrode of Zn/Fe RFB have the largest charge and discharge capacity, whose the oxidation peak and reduction peak are the largest.When the graphite felt treated at 90 ℃ is used as the electrode of Zn/Fe RFB, the efficiency of coulomb is the highest, and the voltage efficiency, coulomb efficiency and energy efficiency are 84 %, 82 % and 62 %, respectively.