A method for preparing a carbon-coated ternary positive electrode material has steps of preparing a ternary positive electrode material precursor, and preparing a suspension of the ternary positive electrode material precursor. Lithium acrylate is added to the suspension of the ternary positive electrode material precursor according to the molar ratio of Li:(Ni+Co+Mn) being 1.03-1.05:1. Ammonium persulphate is added to the lithium acrylate-containing suspension of the ternary positive electrode material precursor, so that the lithium acrylate undergoes a polymerisation reaction and a suspension of a lithium polyacrylate-coated ternary positive electrode material precursor is obtained. The suspension of the lithium polyacrylate-coated ternary positive electrode material precursor is dried to obtain spherical particles. The lithium polyacrylate-coated ternary positive electrode material precursor particles are sintered to obtain a carbon-coated ternary positive electrode material.