Disclosed are a ternary cathode material and a preparation method and application thereof. The ternary cathode material has a chemical formula of LiNix CoyMn(1-x-y)MO2, wherein 0.5≤x≤1, y≥0, M is at least one selected from the group of niobium, boron and titanium. In the present disclosure, through the reaction between the niobium compound, the boron compound or the titanium compound with the residual lithium on the surface of the calcinated materials, the micro powder deposits in the defect position of the lithium crystal lattice on the surface of the calcinated material, so that the content of the micro powder can be greatly reduced. Meanwhile part of the surface residual lithium is consumed by the reaction to generate lithium niobate, lithium borate or lithium titanate which is uniformly coated on the surface of the material, thereby obtaining the ternary cathode material with excellent cycle and rate performance.