The desulfurization law of high sulfur petroleum coke was studied by chemical oxidation method. In this paper, hydrogen peroxide was used as oxidant, formic acid, acetic acid and propionic acid were used as catalysts. The influences of petroleum coke particle size, the ratio of oxidant volume and petroleum coke mass (liquid⁃solid ratio), reaction time and reaction temperature on the desulfurization effect were investigated. The experimental results show that the desulfurization effect of hydrogen peroxide⁃formic acid oxidation system is the best, which is better than the other two oxidation systems. The petroleum coke particle size is 100 mesh, the liquid⁃solid ratio is 20 mL/g, the oxidation reaction time is 18 hours, and the reaction temperature is 60 ℃ for oxidation. Under the optimum conditions of the desulfurization experiment, the sulfur content of petroleum coke decreased from 3.32% to 2.65%, and the desulfurization rate reached 20.2%.