Base on the twostep method, ionic liquid \[BPy\]\[CF3SO3\] was synthesized from 1,4Butane sultone, ridine trifluoromethane sulfonic acid and py. Oxidationextraction desulfurization of model oil has been carried out with the ionic liquid as catalyst and 30% H2O2 as the oxidant. Desulfurization rate of model oil could reach to 94%, when treating 10 mL model oil with 0.6 g ionic liquid, 0.2 mL H2O2 at 50 ℃ for 30 min. After drying with rotary evaporator, the ionic liquid was regenerated for nextrun use, and the desulfurization rate could be still as high as 70% after recycling 5times.