A method of manufacturing a cathode active material coating solution for a secondary battery capable of forming a metal oxide coating layer, the method comprising: preparing a mixed solution by dispersing a metal precursor and a chelating agent in a glycol-based solvent; performing primary heating on the mixed solution, wherein the performing of the primary heating is performed in a temperature range of 110° C. to 230° C. for 5 hours to 20 hours; and performing secondary heating on the mixed solution, wherein the performing of the secondary heating is performed in a temperature range of 170° C. to 250° C. for 1 hour to 5 hours, wherein a temperature of the primary heating is different from that of the secondary heating, and wherein the coating solution is a metal glycolate coating solution comprising at least one metal organo-compound selected from the group consisting of compounds represented by Chemical Formulae 1 to 3 in which a metal desorbed from a metal precursor, a glycol-based solvent, and a chelating agent are combined: [Chemical Formula 1] M(C 2 H 5 O 2) n [Chemical Formula 2] M(C 6 H (8-n) O 7) [Chemical Formula 3] M(C 6 H (8-n) O 7)(C 2 H 5 O 2) where M, as the metal desorbed from the metal precursor, represents at least one metal selected from the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), yttrium, titanium (Ti), zirconium (Zr), vanadium, niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten, manganese (Mn), iron (Fe), cobalt (Co), iridium (Ir), nickel (Ni), zinc (Zn), aluminum (Al), gallium (Ga), indium (In), silicon (Si), germanium (Ge), tin (Sn), lanthanum (La), and cerium (Ce), and n is an integer between 1 and 4. preparing a mixed solution by dispersing a metal precursor and a chelating agent in a glycol-based solvent; performing primary heating on the mixed solution, wherein the performing of the primary heating is performed in a temperature range of 110° C. to 230° C. for 5 hours to 20 hours; and performing secondary heating on the mixed solution, wherein the performing of the secondary heating is performed in a temperature range of 170° C. to 250° C. for 1 hour to 5 hours, wherein a temperature of the primary heating is different from that of the secondary heating, and wherein the coating solution is a metal glycolate coating solution comprising at least one metal organo-compound selected from the group consisting of compounds represented by Chemical Formulae 1 to 3 in which a metal desorbed from a metal precursor, a glycol-based solvent, and a chelating agent are combined: [Chemical Formula 1] M(C 2 H 5 O 2) n [Chemical Formula 2] M(C 6 H (8-n) O 7) [Chemical Formula 3] M(C 6 H (8-n) O 7)(C 2 H 5 O 2) where M, as the metal desorbed from the metal precursor, represents at least one metal selected from the group consisting of magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), yttrium, titanium (Ti), zirconium (Zr), vanadium, niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten, manganese (Mn), iron (Fe), cobalt (Co), iridium (Ir), nickel (Ni), zinc (Zn), aluminum (Al), gallium (Ga), indium (In), silicon (Si), germanium (Ge), tin (Sn), lanthanum (La), and cerium (Ce), and n is an integer between 1 and 4.