Oxidative desulfurization of diesel via ultrasound irradiation was studied in the experiment, and then an adsorption process by active carbon follows. Oxidative desulfurization was carried out by catalyst via ultrasound with H2O2 as an oxidant, acid mixture with V（H3PO4）∶V（H2SO4）1∶1 as reaction medium. Activated carbon would be pretreatment by different methods. The effect of the different activated carbon on sulfur removal rate of oxidized diesel oil was investigated. The result of the experiment indicates that the sulfur removal rate would reach 97.70 % when the oxidation diesel oil is washed by KOH before adsorption over activated carbon treated by nitric acid, and the oil yield would be 91.05 %.