The nanocomposite hydrogen storage materials Zro.sTio.iNio.ssVo.izMnosCoo.os.o-/'oMg were prepared by high temperature sintering treatment. XRD and SEM analyses show that its microstructure is composed of MgCu2-type cubic structure CIS-Laves phase and hexagonal structure Mg, both no alloying effect. AB2 particles and Mg particles were unevenly mixed, and enriched Mg was found in some zone. Transmission Electron Micrographs and SAED patterns show that in the composite material the grain size of AB2 and Mg is in nanometer-sized range. In ultra-big current(lOC), the declining rates of BMS electrodes capacities are obviously lower than those of MMS, the ultra-big current discharge performance of BMS(l2-10%Mg)electrode is best. During ultra-big current discharging (10C), the charge transportation control stands at the lead leaded; however, BMS (i4B2-10%Mg)electrode has a cooperative effect of the charge transportation control and the hydrogen-diffusion control and shows a higher discharge capacity.