Nano-TiO2 was prepared in [Bmim]BF4 ionic liquid, (IL) via microwave radiation. The [Bmim]BF4 IL that Contained the as-prepared TiO2 was mixed with dibenzothiophene (DBT) in n-octane, which was used as model oil for pholocatalytic desulfurization under the UV irradiation. In this process, IL was used not only as Microwave absorption medium for preparation of TiO2, but also as extractant for DBT. The effect of microwave time on the photocatalytic desulfurization ability of prepared TiO2 in the presence of O-2 was investigated. 98.2% and 94.3% sulfur could be removed from model oil and actual diesel oil, respectively, in 10 h UV irradiation under the conditions that V(IL)/V(oil) = 1:5, air flow = 200 mL/min. The (Bmim]BF4 IL was recycled five times with a slight decrease in desulfurization efficiency.