Abstract: Fe3O4 nanoparticles were prepared by chemical co-precipitation，and magnetic composite nanoparticles of SiO2/Fe3O4 and Al2O3/SiO2/Fe3O4 with core-shell structure were obtained by coating SiO2 or Al2O3/SiO2 in situ through carbonation precipitation of Na2SiO3 and NaAlO2. The composite nanoparticles were characterized using X-ray diffraction（XRD），scanning electron microscopy（SEM），Fourier transform infrared spectroscopy（FT-IR）and vibration sample magnetometer（VSM）. Supported metal catalysts were prepared by loading Ru and Ru-Co on the surface of magnetic composite nanoparticles，the catalytic activity of which were evaluated in toluene hydrogenation. The magnetic catalyst of Ru/pvp/SiO2/Fe3O4 showed high activity and could be recycled for six times without activity loss. While the catalyst of Ru/pvp/Al2O3/SiO2/Fe3O4 showed a higher activity at the beginning，and a little activity decrease in the later recycles. The bimetallic catalyst of Ru-Co showed activity strongly related to the formulation and composition，which was found in the order of RushellCocore＞Ru-Co＞CoshellRucore. The catalyst of RushellCocore/SiO2/Fe3O4 with 1∶5 of Ru/Co exhibited excellent activity for of toluene hydrogenation with a TOF of 16 656，which is higher than that of the monometallic Ru/pvp/SiO2/Fe3O4（9828 TOF）under the same reaction conditions.