The invention discloses a preparation method of hollow spherical nickel-cobalt-lithium manganate capable of adjusting pore diameters automatically. The method comprises the steps that 1, a manganese salt/nickel salt mixed solution, a sodium carbonate solution and a sodium hydroxide solution are prepared with deionized water, wherein the molar ratio of manganese salt to nickel salt is 1:1, the molar concentration of manganese salt is 0.1-1 mol/L, the molar concentration of sodium carbonate is 0.1-1 mol/L, and the molar concentration of sodium hydroxide is 0.1-1 mol/L; 2, the sodium carbonate solution is dropwise added into the manganese salt/nickel salt mixed solution for a reaction for 0.5-2 h, then the sodium hydroxide solution is dropwise added into the mixed solution for another reaction for 0.5-2 h, and then drying is carried out after filtering/washing; 3, obtained sediment is calcined at the temperature of 350-600 DEG C to obtain a precursor, the molar ratio of Mn to Li to Co is 1:3:1 after the precursor is mixed with cobalt salt and lithium salt, the mixture is calcined at the temperature of 800-950 DEG C for 2-10 h, and a nickel-cobalt-lithium manganate ternary material can be obtained.