Bio-oil was degraded by the heavy oil from biomass alcoholysis. Therefore，the hydrorefining of heavy oil was studied in the presence of V-W-Mo-Cu catalyst in this paper.The results showed that the catalyst revealed its reactivity only at above 330 ℃，and achieved the highest light oil yield of 93 % at 450 ℃. The extension of hydrogenation time was beneficial to the polymerization of heavy oil at low reaction temperature and the depolymerization at high reaction temperature. Meanwhile，the saturation of depolymerization fractions can be performed，and the yield of light oil from heavy oil hydrogenation can be promoted when the initial hydrogen pressure was increased to 6 MPa. The gas chromatography- mass spectrometry (GC- MS) analysis on light oil indicated that heavy oil could be cracked into micromolecule arene and phenolic compounds after hydrogenation，including 2-ethyl-1-methyl-benzene，butylbenzene，3-ethenyl-1-ethyl-benzene and phenol. However，the Fourier transform infrared spectrometer (FTIR) analysis on catalyst after hydrogenation showed that heavy oil also could be polymerized into macromolecule arene and phenolic polymer. After being baked at 550 ℃，the catalyst could be reused more than 5 times，and the yield of light oil was still up to 70 %.