Abstract: The innovative nuclear reactors with the characteristics of flexible function, high safety and efficiency, multipurpose are developing fleetly. The conventional scheme, widely used high-temperature and high-pressure water as the neutron moderator material, can no longer meet the higher temperature and compacter requirements for new reactors. Compared with pure water and liquid hydrogen, metal hydrides, especially zirconium hydride and yttrium hydride, own the same or even higher hydrogen atom concentration, superior moderation performance, higher applicable temperature and smaller volume. So metal hydrides make the reactor core layout more flexible, and have become the key research and development objects of high-temperature moderator materials. In this paper, the key service properties of yttrium hydride are summarized, and compared with that of zirconium hydride briefly. Compared with zirconium hydride, yttrium hydride has the advantages of superior high-temperature stability, higher thermal conductivity, no mutation in thermal expansion process and higher applicable temperature. Yttrium hydride can meet the requirements of higher core design and shows great application potential in the compact reactor technology.