The phase transformation law of hydrochloric acid dissolved high pure aluminum ash were investigated by XRF, SEM, XRD and other analytical methods. The results indicate that the high-purity aluminum ash is composed of long strip, columnar, rodlike and spherical particles with phases composed of Al, Al₂O₃, Al₂OC and BaO etc., and acid-leached residue phases are AlN, Al₂O₃ and Al（OH）₃. In hydrochloric acid, the dissolution rate is increased with the increase of liquid-solid ratio and temperature, which reaches the maximum value at 65 ℃. The phase containing Al is transformed into [AlCl₃（H₂O）₆] during acid leaching. The structure of formed polymeric aluminum is transformed from tetrahedron and octahedron to polymers, where a stable six-membered ring structure is formed by hydroxyl group, and the monomer is polymerized with hydroxyl group on the six-membered ring at a vertex H to form a plug-in multi-dimensional network structure.