  High-pressure structural search was performed on the hydrogen-rich compound
LuBeH$_8$ at pressures up to 200 GPa. We found a $Fm\overline{3}m$ 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 $T_{c}$ shows a decreasing trend as the pressure increases,
with a superconducting critical temperature $T_c$ of 255 K at 200 GPa and a
maximum $T_c$ of 355 k at 100 GPa. Our research has demonstrated the
room-temperature superconductivity in $Fm\overline{3}m$-LuBeH$_8$, thus
enriching the family of ternary hydrides. These findings provide valuable
guidance for identifying new high-temperature superconducting hydrides.
