A method for preparing a precursor of a positive electrode active material for a secondary battery comprising a single layer-structured secondary particle in which pillar-shaped primary particles radially oriented in a surface direction from the particle center are aggregated, wherein the secondary particle has a shell shape; and the primary particle includes a composite metal hydroxide of Ni-Co-Mn of the following Chemical Formula 1: [Chemical Formula 1] Ni 1-(x+y+z) Co x M y Mn z 2 wherein, in Chemical Formula 1, M includes any one, or two or more elements selected from the group consisting of Al, Zr, Mg, Zn, Y, Fe and Ti; and x, y and z are each 0<x<1, 0≤y<1, 0<z<1 and 0<x+y+z<1, the method comprising: preparing a metal-containing solution by mixing a nickel raw material, a cobalt raw material and a manganese raw material and adding an M raw material when mixing each of the nickel raw material, a cobalt raw material and a manganese raw material; and and introducing an ammonium cation-containing complex forming agent and a basic compound to the metal-containing solution and co-precipitation reacting the result under a pH of 10.50 to 12.00 and a temperature of 50°C to 70°C, wherein the ammonium cation-containing complex forming agent is introduced at a rate of 0.5 times to 1.5 times with respect to an introduction rate of the metal-containing solution. wherein the secondary particle has a shell shape; and the primary particle includes a composite metal hydroxide of Ni-Co-Mn of the following Chemical Formula 1: [Chemical Formula 1] Ni 1-(x+y+z) Co x M y Mn z 2 wherein, in Chemical Formula 1, M includes any one, or two or more elements selected from the group consisting of Al, Zr, Mg, Zn, Y, Fe and Ti; and x, y and z are each 0<x<1, 0≤y<1, 0<z<1 and 0<x+y+z<1, the method comprising: preparing a metal-containing solution by mixing a nickel raw material, a cobalt raw material and a manganese raw material and adding an M raw material when mixing each of the nickel raw material, a cobalt raw material and a manganese raw material; and and introducing an ammonium cation-containing complex forming agent and a basic compound to the metal-containing solution and co-precipitation reacting the result under a pH of 10.50 to 12.00 and a temperature of 50°C to 70°C, wherein the ammonium cation-containing complex forming agent is introduced at a rate of 0.5 times to 1.5 times with respect to an introduction rate of the metal-containing solution. M includes any one, or two or more elements selected from the group consisting of Al, Zr, Mg, Zn, Y, Fe and Ti; and x, y and z are each 0<x<1, 0≤y<1, 0<z<1 and 0<x+y+z<1, the method comprising: preparing a metal-containing solution by mixing a nickel raw material, a cobalt raw material and a manganese raw material and adding an M raw material when mixing each of the nickel raw material, a cobalt raw material and a manganese raw material; and and introducing an ammonium cation-containing complex forming agent and a basic compound to the metal-containing solution and co-precipitation reacting the result under a pH of 10.50 to 12.00 and a temperature of 50°C to 70°C, wherein the ammonium cation-containing complex forming agent is introduced at a rate of 0.5 times to 1.5 times with respect to an introduction rate of the metal-containing solution. preparing a metal-containing solution by mixing a nickel raw material, a cobalt raw material and a manganese raw material and adding an M raw material when mixing each of the nickel raw material, a cobalt raw material and a manganese raw material; and and introducing an ammonium cation-containing complex forming agent and a basic compound to the metal-containing solution and co-precipitation reacting the result under a pH of 10.50 to 12.00 and a temperature of 50°C to 70°C, wherein the ammonium cation-containing complex forming agent is introduced at a rate of 0.5 times to 1.5 times with respect to an introduction rate of the metal-containing solution.