A preparation method of a hollow nickel nanosphere is characterized in that the steps included in the method are as follows: (1) uniform silica colloidal solution is prepared by adding distilled water to silica nanoparticles; and nickel nitrate hexahydrate and urea are dissolved in the distilled water; (2) a light green uniform system is obtained by mixing the solution in the above step and adding the distilled water, and the light green particles deposit after cooling; and once particle outer coating is completed and multiple particle outer coatings can be completed through repetition; (3) the light green particle precipitate is obtained by adding the coated light green particles to NaOH solution for soaking and core etching; (4) the light green particles are cleaned by the distilled water and then dried in vacuum to obtain the dry powder; (5) the dry powder is reduced with hydrogen; and (6) the cooling preservation is carried out with nitrogen or inert gas. Compared with the prior art, the preparation method has the advantages that the metal content on a carrier is high, and the hollow nickel nanospheres with different inner diameters and shell thicknesses can be synthesized in large amount as required through using diaphragm plates with different sizes and changing different coating times.