Oxygen reduction reaction (ORR) not only needs the excellent electrode materials, but also requires quick mass transfer of dissolved oxygen. To strengthen the ORR and O-2(-) oxidation desulfurization, pressurized water electrolysis was carried out in this work. The results showed that the desulfurization ratio increased with increasing pressure, indicating that the pressure has strengthened the O-2(-) generation. As expected, the ORR initial potential shifted from -0.034 V to -0.030 V with increasing pressure from 0.1 Mpa to 2Mpa. The peak current, the limit current density and the peak integral area all increased with increasing pressure. On the other hand, the reduction in solution resistance (R-s) and reaction resistance (R-ct) further verified that the pressure can strengthen the transfer of dissolved oxygen and the ORR dynamics. More importantly, the pressure has improved O-2(-) generated potential in a large parameter window (the width of the metastable zone, the difference between the initial potential and the peak potential of the ORR). The pressure could enhance the O-2(-) formation, and improve the desulfurization process. (C) 2018 The Electrochemical Society.