Herein, we successfully prepared a 3D hierarchical microsphere AlV3O9 electrode material composed of nanosheets, which is used as a cathode material for aluminum ion batteries, AlCl3 and [EMIm]Cl as its electrolyte, and aluminum metal as an anode electrode. Its microstructure and crystal structure were characterized by SEM and TEM. The energy storage mechanism was obtained by XPS analysis. It was found that Al3+ reversibly intercalates and de-intercalates into the AlV3O9 electrode material, and phase transition occurs at the electrode material interface. The pseudocapacitive behavior of the electrode materials was investigated by cyclic voltammetry. The AlV3O9 electrode material also exhibits excellent electrochemical performance. The initial discharge specific capacity is as high as 327 mA h g−1 at a current density of 100 mA g−1, and the coulombic efficiency is also close to 100%. This lays a theoretical foundation for the further commercial application of aluminum ion batteries.