The invention provides a preparation method of a 3D sea urchin spherical carbon-based nickel-cobalt bimetallic oxide composite material, comprising the following steps: 1) multi-wall carbon nanotubesand concentrated nitric acid are ultrasonically mixed evenly, processed by an oil bath, filtered, washed and dried to obtain acidified multi-wall carbon nanotubes; 2) prepare metal ion solution, adding acidify multi-wall carbon nanotubes, uniformly stirring, dropping acid-base regulator to adjust pH to obtain mixed solution; 3) transfer that mixed solution into a hydrothermal kettle, heat preservation to complete the reaction, cooling, filtering, washing, dry and grinding to obtain a composite material precursor; 4) that composite precursor is place in an air atmosphere and subjected to low-temperature pyrolysis treatment to obtain a 3D sea urchin spherical carbon-based nickel-cobalt bimetallic oxide composite material. The composite material prepared by the invention is applied in the zinc-air battery and exhibits excellent catalytic performance, so that the battery not only has high energy efficiency, but also has large power density, current density and specific capacity.