To decrease the hydrogen sorption temperature and increase the hydrogen sorption rate is important for the practical application of magnesium for hydrogen storage. The binary nano-catalysts Mg2Ni and Ce6O11 with oxygen vacancy defects was in-situ synthesized on Mg surface via the hydrogen activation of Mg-Ni-CeO2. The hydrogen storage material Mg-20Ni-CeO2 can release 4.19 wt% H2 in 5 min at 320 °C, which is significantly higher than that of Mg with 10 wt% Ni (3.44 wt% H2) or 10 wt% CeO2 (0.34 wt% H2). The peak temperature and apparent activation energy for hydrogen desorption of Mg-20Ni-CeO2 are reduced by 115.8 °C and 63.89 kJ/mol respectively comparing with that without catalyst. Structural analysis suggests that Mg2Ni and Ce6O11 can be in-situ synthesized on Mg surface, which shows a synergistic catalysis for hydrogen storage. During H2 absorption, the oxygen vacancy defects on Ce6O11 surface can trap H2 molecules, while the Mg2Ni on Mg/Mg2Ni interface can promote H2 dissociation. For H2 desorption, the Mg2Ni can weaken the Mg-H bond and act as “hydrogen pump” to transfer H for H2 formation with the assistance of Ce3+/Ce4+ transformation in Ce6O11. The results of this study provide a new horizon for a novel binary catalyst design for hydrogen storage.