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In this work, polyvinylpyrrolidone (PVP) coated Mg95Ni5nano-composites were prepared by hydriding com-bustion synthesis(HCS)plus wet mechanical milling(WM)with tetrahydrofuran(THF)and donated as WM-x wt % PVP(x=1,3,5 and 7)respectively.The phase compositions,microstructures and dehydriding property,as well as the co-effect of PVP and THF were investigated in detail.XRD results showed that the average crystal size of MgH2in the milled Mg95Ni5decreased from 23 nm without PVP to 18 nm with 1 wt% PVP. The peak tem-perature of dehydrogenation of MgH2in the milled Mg95Ni5decreased from 293.0°C without THF to 250.4°C with THF. The apparent activation energy for decomposition of MgH2in WM-7 wt% PVP was estimated to be 66.94 kJ/mol,which is 37.70 kJ/mol lower than that of milled Mg95Ni5without THF and PVP.PVP and THF can facilitate the refinement of particle size during mechanical milling process.Attributed to small particle sizes and synergistic effect of PVP and THF,the composites exhibit markedly improved dehydriding properties.