A three-dimensional electrode system for electrochemical oxidation was developed in which Mn-Sn-Sb complex metal oxides supported on γ-Al2O3 were packed between the two main electrodes.X-ray diffraction（XRD）and scanning electron microscope（SEM）were used to characterize the particle-electrodes.The two-dimensional electrolysis efficiency of phenol degradation without particle-electrodes was 55.6%，while the phenol degradation efficiency with three-dimensional particle-electrodes reached 90.8%.The results showed that the particle-electrodes had good electrocatalytic activity and stability for the degradation of phenol.It was found that phenol degradation followed a pseudo-first-order reaction kinetic model.Analysis of the treated aqueous solution was conducted with GC-MS，and the main intermediates during phenol degradation were isobutyric acid，malonic acid，benzoquinone，butenoic acid，oxalic acid，maleic acid，succinic acid，hydroquinone，catechol and resorcin.According to the GC-MS analysis，a possible pathway for the electrochemical oxidation of phenol was presented.