Citric acid type deep eutectic solvent was synthesized using citric acid（CA） and choline chloride (ChCl) as raw materials. The existence of hydrogen bonding in deep eutectic solvents (DESs) was determined by infrared spectrum and hydrogen spectra. Sulfide in simulated oil was removed using DESs as extractant and potassium bisulfate as oxidant. The effects of the amount of water, the amount of oxidant, the ratio of hydrogen bond donor and acceptor, reaction temperature and different sulfides on desulfurization rate were investigated, and the optimum reaction conditions were determined. The results showed that the removal rate of DBT in simulated oil was 98.50% at V（model oil）=5 mL, n（ChCl）/n（CA）=1.0∶0.5, V（DES）=2.0 mL, T=30 ℃, m(catalyst)=0.6 g, m(water)=0.4 g. After five times of recycling, the desulfurization rate remains above 95.00%.