  Exploring high-temperature superconducting (high-$T_c$) material at ambient
pressure holds immense significance for physics, chemistry, and materials
science. In this study, we perform a high-throughput screening of strong
electron-phonon interactions in X$_2$MH$_6$ compounds (X = Li, Na, Mg, Al, K,
Ca, Ga, Rb, Sr, and In; M are $3d$, $4d$, and $5d$ transition metals). These
compounds have a cubic structure featuring an MH$_6$ octahedron motif. Our
screening calculations suggest that 26 compounds exhibit dynamic stability and
strong electron-phonon coupling. Among these 26 compounds, Mg$_2$RhH$_6$,
Mg$_2$IrH$_6$, Al$_2$MnH$_6$, and Li$_2$CuH$_6$ show promising energetic
stability and $T_c$ of more than 50 K at ambient pressure. This study
underscores promising high-$T_c$ compounds at ambient pressure with distinctive
MH$_6$ motifs.
