By using a self-made carbon/polytetrafluoroethylene (C/PTFE) O2-fed as cathode and Ti/IrO2/RuO2 as anode, the effects of electrochemical oxidation of phenol and the coal-gas wastewater containing phenol were studied. The terylene diaphragm which kept pH>12 in cathodic compartment and pH＜1 in the anodic compartment was selected in the experiment in comparison with the other ctron spin resonance spectrum(ESR) and the fluorescence spectra. Compared with pH, the accumulated H2O2 and the COD removal of the no-diaphragm cell, the mechanism of electrochemical oxidation in the terylene diaphragm cell was supposed. The degradation of by oxygen reduction at the cathode. The mineralization of phenol in the diaphragm cell was better than that in the no-diaphragm cell.When the coal-gas wastewater was treated by the electrolysis system with terylene diaphragm, the average removal efficiency of the volatile phenol and COD were 100% and 79.6%, respectively.