A photochemical oxidation and ionic liquid ([Bmim]PF6) extraction coupling technique was employed in deep desulphurization of light oil with the presence of photo oxidant H2O2. In this process, [Bmim]PF6 was utilized to be the extractant and photochemical reaction medium to promote the oxidation of dibenzothiophene (DBT). The deep oxidative desulfurization, 99.5% removal rate of DBT from n-octane and 90.6% sulfur removal rate of actual light oil, was achieved under mild conditions of room temperature and atmospheric pressure. The ionic liquid [Bmim]PF6 was recycled eight times with a slight decrease in desulfurization efficiency.