The invention discloses a ternary positive electrode material coated with nitride/graphitized carbon nanosheets and preparation method thereof. The ternary positive electrode material coated with nitride/graphitized carbon nanosheets includes a ternary positive electrode material matrix and a coating layer; the coating layer is composed of nitride and graphitized carbon; and the graphitized carbon is formed in situ in the coating process of the nitride. Compared with a physical mixing method, the in-situ generated carbon layer is connected to the material matrix more tightly, and the formed conductive network is denser. So that the rate performance of the material is improved to the maximum extent. The preparation method is simple and easy to realize industrial production. And the obtained ternary positive electrode material coated with nitride/graphitized carbon nanosheets has excellent rate performance and cycling stability.