In this paper, we applied ball milling technique to prepare amorphous and nanocrystalline CeMg11Ni + x wt.% Ni (x = 100, 200) alloys which gaseous and electrochemical hydrogen storage dynamics and structure characteristics were systematically studied. It is shown that increasing Ni proportion promotes the amorphization of alloys, meanwhile, it improves their gaseous and electrochemical hydrogenation dynamics significantly. Besides, adjusting milling duration markedly changes the hydrogen storage performances. With the prolonging of milling time, the hydrogen storage capacity has a maximal value, which are 5.949 wt.% and 6.157 wt.% respectively for x = 100 and 200 alloys, while the dehydriding rate always increases. The hydriding rate and high rate discharge ability have the maximal values with the variation of milling time as well. The improved gaseous hydrogen storage dynamics is convinced to be connected with the reduction of dehydrogenation activation energy resulted by increasing Ni proportion and prolonging milling duration.