Commercial clay modified with metal halides was prepared to remove olefins from aromatics in the laboratory, and its industrial test was conducted. Different amounts of metal-halides-modified clay were made and characterized by XRD and pyridine adsorption followed by FT-IR. The type and nature of active sites in the removal of olefins over the prepared catalysts have been examined. The study of acidic properties of the modified clay revealed that the L acid, especially the weak L acid plays an important role in the reaction. The experimental results revealed that commercial clay modified with metal halides had much better catalytic activity. During Sinopec Qilu company industrial test, modified clay had an effective running time six times as long as that of untreated commercial clay.