Hydrous silicate phase D is considered to be a potentially important carrier and reservoir in Earth’s deep interior. The experiments aim to investigate the crystal structural evolution, thermal equation of state, spin state of iron, and hydrogen bond configuration in (Fe2+, Fe3+)-bearing Al-Phase D utilizing the Single-Crystal X-ray diffraction and Synchrotron Mössbauer Source spectroscopy at high pressure-temperature conditions (up to 80 GPa and 1200 K), and to determine their potential influences on the properties of the Earth’s deep interior.