The invention relates to a rare-earth doping modified lithium ion battery ternary positive electrode material and a preparation method of the rare-earth doping modified lithium ion battery ternary positive electrode material. The chemical general formula of the material is as follows: LiNiaCo<1-a-b>MnbRxO2/M, wherein a is more than 0 and less than 1, b is more than 0 and less than 1, (1-a-b) is more than 0 and less than 1, x is more than 0.005 and less than 0.1, R is one or more of rare-earth lanthanum, cerium, praseodymium and samarium, and M is a composite cladding layer of oxide of aluminum, titanium or magnesium and carbon. The soluble metal nickel salt, cobalt salt, manganese salt and rare-earth compound are mixed to prepare a mixed salt solution, the mixed salt solution is reacted with a mixed alkaline solution prepared by mixing NaOH and ammonium hydroxide, after the reaction solution is filtered, washed and dried, the obtained product is uniformly mixed with lithium salt powder to be ball milled, then the mixture is calcined at the high temperature and coated with the composite cladding layer of the aluminum, titanium or magnesium oxide and carbon, and finally the calcined mixture is calcined at a constant temperature to obtain the rare-earth doping modified lithium ion battery ternary positive electrode material. After doping the rare earth, the metal oxide and carbon composite cladding layer, which are cheap and easy to obtain, are adopted, so that the cycling performance and the rate performance can be improved, and the charging-discharging efficiency of the material also can be improved.