The sulfur - bearing organics in diesel oil was oxidized using H2O2 - CH3COOH systems via microwave irradiation，then the oxidized organic sulfur compounds (sulfones) were extracted by N,N - dimethyl formamide. Experimental results show that the removal efficiency of sulfur compounds is up to 88.2％ in the following conditions：the dosage of the oxidant is 12 times as much as that of theoretical, the volume ratio of solvent-to-oil is 0.25∶1, the pressure is 0.4 MPa, the radiant time on the constant pressure is 6 min, the microwave power is 375 W，the volume ratio of extractant-to- oil is 0.25∶1, the standing time is 10 min. Compared with other methods on oxidative desulfurization, the removal efficiency of sulfur can increase 26%～42% and the dosage of the oxidant reduce 20%~50%.