The invention is applicable to the technical field of lithium batteries and provides a preparation method of a ternary positive electrode material doped with Er and Zr metal ions. The preparation method includes a step of pre-sintering, a step of preparing a doping element solution, a step of mixing, a step of hydrothermal treatment, and a step of drying, and a step of sintering. The preparation method pre-sinters a NCA precursor into a porous honeycomb-shaped spheroidal pre-sintered precursor by a pre-sintering method, then prepares a solution with Er and Zr sources in proportions, mixes thesolution with the pre-sintered precursor under a water condition, effectively introduces the Er and Zr solution into the positive electrode material substrate through honeycomb-shaped holes, then addslithium, melts the Er and Zr sources, the substrate, and the lithium source under hydrothermal and high temperature and high pressure conditions for sufficient and effective reaction, finally sintersthe material at a high temperature, and crystallizes the finished product to obtain a doped nickel-cobalt-aluminate positive electrode material. Zr4<+> can reduce cation mixing, and Er3<+> can reducepolarization and enhance electrochemical performance, so that Er3<+>/Zr4<+>, during charging, does not undergo electrochemical reaction, has no change in valence, and can play a role in stabilizing the crystal structure.