A recycling process for the demetalization of hydrocarbon oil comprises recycling the following steps:a demetalizing composition for hydrocarbon oil or an aqueous solution thereof is sufficiently mixed with hydrocarbon oil in a desired proportion, and the resultant mixture is subjected to a conventional electrically desalting process to obtain a demetalized hydrocarbon oil and an aqueous desalted solution containing the desalted metal salts;the aqueous desalted solution containing the metal salts is then sufficiently mixed with a precipitating agent in a desired proportion and is subjected to a displacement reaction, and an aqueous solution containing the demetalizing composition is recovered by separating out the residue of the metal salts produced in the displacement reaction, which is poorly soluble or insoluble in water, with a solid-liquid separator; andthe recovered aqueous solution containing the demetalizing composition for hydrocarbon oil, which meets the requirements for metal ions in demetalized hydrocarbon oil, is then mixed with hydrocarbon oil in a desired proportion for a next cycle.The present invention has the following advantages such as high efficiency of demetalization, reduction of pollution to the environment and the production cost as well as the metal salt product obtained by treating and collecting the desalted residue of the metal salt.