The invention discloses an aromatic solvent oil refining agent and a preparation method. The aromatic solvent oil refining agent uses metal and organic compounds to modify the surface of an adsorbent; the content of metal is 0.1-10wt%, the content of organic compounds is 0.1-2wt%, the balance is silicon dioxide in mass , the specific surface area is 300-600m<2>/g, and the surface total acid content is 0.05-0.40mmol/g. The preparation method comprises the following steps of mixing water glass and sulfate according to ratio, and preparing into a sol; washing the sol by deionized water, pulping, spraying, and drying, so as to obtain granular small balls; impregnating the granular small balls by metal salt, modifying, drying, and roasting, so as to obtain a metal-modified granular carrier; using organic hydrocarbon with low boiling point as a solvent, using one or several of alcohol, polyhydric alcohol and nitrogen-containing compounds as a solute, preparing a mixing solution, and modifying the carrier by the organic solvent; drying, so as to obtain the aromatic solvent oil refining agent. The aromatic solvent oil refining agent has the advantages that the arene in the solvent oil can be effectively extracted and purified, the content of arene in the prepared aromatic solvent oil is greater than 95%, and the aromatic solvent oil refining agent can be applied to the refining of aromatic solvent oil and the extraction and purification of arene.