The invention discloses a technology of plating the surface of cubic boron nitride with a CuO film. The technology comprises the steps that Cu(OEt)2 is adopted as an organic precursor, ammonium hydroxide is dropwise added into the mixed liquid of Cu(OEt)2 and triethanolamine, the Cu(OEt)2 is subjected to controlled hydrolysis, and stable Cu(OH)2 sol is prepared; the Cu(OH)2 sol is used for dipping a surface-treated CBN grinding material, the grinding material is tanked out of sol, dried, roasted at the specified temperature, screened and selected, and the CBN grinding material with the surface evenly plated with the CuO film is obtained. By means of the CuO film, the wettability of the CBN grinding material and a metal bonding agent can be improved, the holding force of the metal bonding agent for the CBN grinding material is improved, and the service life of a CBN metal grinding tool is prolonged.