Various MgO-Al2O3-CeO2 supported Ni catalysts with different CeO2 content (5-15wt.%) were successfully synthesized via two-step hydrothermal process and applied in the CO methanation reaction. The catalytic tests proved that the added CeO2 efficiently improved the catalytic activity due to improving the formation of oxygen vacancies, which could accelerate CO methanation. Meanwhile, CeO2 content influenced the reaction performance in the CO methanation, and the catalyst with 10% CeO2 content showed the highest activity and excellent thermal stability. The catalysts were characterized by XRD, BET, SEM, TEM, H-2-TPR, XPS and TG-DSC.