Abstract: In order to trap the heavy metal Ni and V in Oman crude oil and reduce their influence on the subsequent processing, With NaBH4 as a H2O reducing agent for producing H2, CrCl3 ? 6 H2O was used as a metals trapping agent to investigate the effect of metal capture agent amount, reaction temperature and reaction time on the metal capture in the hydrogen atmosphere. Results show that the optimal conditions are: a temperature of 150 ℃, NaBH4 and CrCl3 of 0.07 % and 0.12%, respectively, reaction time of 3 h. The trapping rates of Ni and V reach 71.23% and 46.47%, respectively under the best conditions. The mechanism of trap effect explore results shows that under the hydrogenation condition, the outer ring of etioporphyrin nickel is hydrogenated, the N-Ni bonds are broken and Ni2+ is removed from the prophyrin ring. Compared with Ni2+, Cr3+ has a stronger binding energy and Cr3+ replaces Ni2+ and generates more stable metal complex.