Abstract: Pd/Ni/Al2O3 and Pd/Al2O3 catalysts having the same Pd content were prepared by kneading-impregnating method and characterized by XRD, BET and NH3-TPD techniques. The selective hydrogenation performance of the prepared catalysts was evaluated on a fixed bed continuous micro-reactor device using heavy reforming aromatic oil as feed. Test results showed that Pd/Ni/Al2O3 catalyst having γ-Al2O3 phase, suitable specific surface area and pore size distributions with less acid amount, exhibited better selectivity to olefin conversion and stability in selective hydrogenation of heavy reforming aromatic oil as compared with Pd/Al2O3 catalyst. The optimum reaction conditions were as follows: a reaction temperature of 80 ℃，a reaction pressure of 5 MPa，LHSV of 2 h-1 and H2/oil volume ratio of 500.