The work aims to reveal the effects of the maximum concentration of hydroxyl radicals (?OH) and the total concentration of ?OH generated by the Electro-Fenton parameters, so as to maximize the Electro-Fenton reaction on single crystal 6H-SiC oxidation corrosion. The influence rules of the voltage, electrode types, oxidant concentration of hydrogen peroxide (H2O2), catalyst types, catalyst concentration, and reaction solution pH and other parameters were optimized through the six-factor five-level orthogonal experiment to generate maximum concentration of ?OH and total concentration of ?OH and find the best experimental combination and main influencing factors were found. Then, the optimal experimental combination and Fenton reaction under the same conditions were used to compare and analyze on the single crystal 6H-SiC oxidation corrosion. The order of factors influencing the maximum concentration of ?OH and the total concentration of ?OH generated by the Electro-Fenton reaction was catalyst type > voltage > H2O2 concentration > catalyst concentration > pH> electrode type; of which, catalyst type, voltage, and oxidant concentration had significant effects, with impact factors of 45%, 22%, 12% and 30%, 19%, 41%, respectively. Compared with the Fenton reaction under the same conditions, the maximum concentration of ?OH and the total concentration of ?OH produced by the Electro-Fenton reaction increased by 61.34% and 68.62%, respectively, and more SiO2 oxide layers could be formed on the 6H-SiC surface. The Electro-Fenton reaction can accelerate the conversion of Fe3+ to Fe2+ and generate a portion of H2O2 in situ by controlling the electrical parameters, supplement the consumption of H2O2 during the reaction, increase the total concentration of ?OH produced, and accelerate the oxidative and corrosive effect of ?OH on the single crystal SiC substrate.