Electrocatalysis on the degradation of methyl orange is investigated using Sb2O3-loaded activated carbon (Sb2O3/AC), a new particle electrode. The electrode was prepared by an impregnation method. An orthogonal array with four factors and three levels was selected to carry out the experiment. Electrocatalysis on the degradation of methyl orange through Sb2O3/AC was characterized by a series of parameters, including the amount of the particle electrode, the concentration of Na2SO4, the cell voltage, and the electrolysis time, and the results were compared with those of a conventional AC particle electrode. The results indicate that calcination temperature has the greatest impact on the catalytic activity of the particle electrode. The optimal conditions for preparing the Sb2O3/AC electrode include an 8 mL SbCl3 solution, 90 min hydrolysis time, 400 °C calcination temperature, and 180 min calcination time. As well, the degradation efficiency of the Sb2O3/AC electrode is consistently higher than that of the AC electrode under the same electrolysis conditions. The electrochemical oxidation of methyl orange of both electrodes conformed to pseudo first-order kinetics, but the rate constant of the Sb2O3/AC electrode was 2.29 times that of the AC electrode; this is likely due to the high electrocatalytic activity of the experimental electrode. The electrocatalysis results exhibited the synergetic effects of AC and Sb2O3 in the new particle electrode. [ABSTRACT FROM AUTHOR]