Abstract: The properties of ionic liquids ［BMIM］Br-xFeCl2 (where ［BMIM］ is 1-butyl-3-methylimidazolium cation) during the removal of thiophene were investigated. The result shows that ［BMIM］Br-FeCl2 only interacts with thiophene, and the removal rate of thiophene can reach 39.28%. The increase of the mass ratio of the ionic liquid to the oil, enhancement of the temperature and the increase the molar fraction of ferrum(Ⅱ) chloride in ionic liquids benefit the desulfurization performance. For the ionic liquid ［BMIM］Br-2FeCl2, the thiophene removal rate can be above 90% after mixing with oils with olefin. These results are valuable for the modification of desulfurization technology.