High-pressure structural search was performed on the hydrogen-rich compound LuBeH 8 at pressures up to 200 GPa. We found an Fm3¯m structure that exhibits stability and superconductivity above 100 GPa. Our phonon dispersion, electronic band structure, and superconductivity analyses in the 100–200 GPa pressure range reveal a strong electron–phonon coupling in LuBeH 8 , while the superconducting critical temperature T c shows a decreasing trend as the pressure increases, with T c = 255 K at 200 GPa and maximal T c = 355 K at 100 GPa. This study demonstrated the room-temperature superconductivity in Fm3¯m -LuBeH 8 , thus enriching the family of ternary hydrides. These findings provide valuable guidance for identifying new high-temperature superconducting hydrides.