In this paper, based on CMF high voltage and liquid precipitation method, the ternary precursor is prepared; then by mixing it with lithium carbonate, the analysis is made for their properties through the XRD and thermogravimetry; finally, the ternary cathode material of lithium ion battery is prepared under the high temperature reaction for the mixture of the precursors and lithium carbonate, and the electrochemical properties of the material are investigated. The oxidative dehydration process of the ternary precursor is mainly concentrated at 250°C-350°C under the CMF high voltage. As the temperature increases to 200°C and 300°C respectively, the ternary precursors are developed into Me(OH) 2 and CoNiOOH structures respectively; as the temperature further increases CoNiOOH was anhydrated into Mn (Ni, Co) 2O4, and the material surface becomes very dense; at 300-500°C, the mixture shows the characteristics of the composite oxide (LiNi0.5Co0.2Mn0.3O2); at 600°C above, the diffraction peak belonging to lithium carbonate completely disappears, and LiNi0.5Co0.2Mn0.3O2 is basically generated. The electrochemical analysis of LiNi0.5Co0.2Mn0.3O2 shows that the maximum specific capacity of the battery for the first charge and discharge is 172 mAh/g, and the Coulomb efficiency is 90.1%. When the lithium content in the material is set to be 1.09, the battery parameters such as median voltage and discharge platform all reach the optimal value.