A new method of upgrading 6(#) solvent oils using different ionic liquids as catalysts in a continuous apparatus is studied in this paper. The results show that aromatics, olefins and small quantity of sulfurs can be removed simultaneously. Using complex ionic liquid modified with CuCl as catalyst, olefins are removed completely, the mass concentrations of aromatics and sulfurs in solvent oil are 0.36% and 0.0058%, respectively, and the bromic index is zero. The sulfur removal rate decreases gradually with increasing of running time. The refined 6(#) solvent oil is corresponded to the quality standards of GB16629-1996, which request that the mass concentrations of aromatics, sulfurs and bromic index are 1%, 0.012% and 1000, respectively. The loss of solvent oil is less than 3%.