Ti/IrO2+MnO2 composite electrodes were prepared by thermal decomposition. The kinetics of oxygen evolution reaction on Ti/IrO2+ MnO2 electrodes were studied deeply with quasi-stationary polarization curve recorded by slow linear potential sweep voltammetry. The related kinetics parameters, reaction process and rate determining steps were obtained. Tafel linear regions wih double slopes were explained well by analyzing the ohmic voltage drop corrected Tafel curves. Kinetics equations based on the proposed oxygen evolution reaction mechanism were deduced mathematically, which were in good agreement with the experimental results. The reaction order of hydrogen ion close to 0, the one of apparent activation energy of 30.31kJ/mol in the low potential region and the other of 13.64kJ/mol in the high potential region, further proved the correctness of above mathematical model.