Abstract Hydrogen storage technology is related to the process of hydrogen energy market. Efficient and safe hydrogen storage materials have always been the goal pursued by people. In the past few years, oceans of materials for hydrogen storage have been researched, MgH 2 is considered to be one of the most potential hydrogen storage materials due to its high hydrogen storage capacity, good reversibility and price advantage. However, its development has been limited by its good thermodynamic stability and slow dehydrogenation kinetics. In this paper, the improvement of hydrogen storage performance of MgH 2 is summarized from catalyst doping, MgH 2 nanosizing, alloying and the construction of composite system. In particular, catalyst doping and MgH 2 nanosizing will be more effective modification strategies. With the development of nanotechnology, monatomic catalyst will also become a research hotspot. In view of the changes in thermodynamic properties caused by the nanofabrication of MgH 2 , the loadless freestanding nano MgH 2 will undoubtedly receive more attention.