Abstract: The low melting point phase, microstructure and fracture morphology of new Al-Zn-Mg-Cu-Li five-element alloy were analyzed by means of optical microscope, X-ray diffractometer, differential scanning calorimeter and scanning electron microscope. The results show that there are non-equilibrium solidified phases（Al ZnMgCu quaternary phase and trace Fe-containing compounds） in the as-cast microstructure.After the double-stage homogenization at 490 ℃/24 h+530 ℃/24 h,the irregular eutectic phase at the grain boundaries of the as-cast microstructure is redissolved, and some massive phases are discontinuously distributed in the grain boundaries, and the grain boundaries become intermittent and clear.