The work aims to investigate the influencing factors of vacuum nickel plating on diamond surface and the feasibility of its application on diamond plating line. EDTA disodium, organic acid and aluminum oxide were coated with different nickel sources according to different mixing ratios at 720 ℃and 6×10-2 Pa vacuum for 2.5 h. The effects of different processes on coating on diamond surface were discussed by characterizing means such as particle size analysis, rapid vibration ball mill, energy spectrum analysis, three-dimensional digital microscope, magnetic test and rapid corrosion test. The diamond centre diameter D50 and peak width (D95-D5, the diamond centre diameter D50 was the maximum equivalent diameter of the diamond particles with a cumulative distribution of 50% in the particle size distribution curve. The D5 and D95 were the maximum equivalent diameters when the cumulative distribution was 5% and 95% in the distribution curve, respectively) increased with the increase of nickel oxide content after plating. D50 and peak width decreased with the increase of EDTA disodium. Organic acid promoted the plating reaction: citric acid>chloroacetic acid>lactic acid. Plating surface obtained by vacuum nickel plating was magnetic nickel metal layer. Diamond strength was not affected by graphitization and did not decline. The bonding between coating and diamond was firm, and acid corrosion resistance was much better than that of electroless nickel plating. The vacuum nickel-plated diamond with nickel chloride as nickel source was sanded on the equipment of buried-sand electroplating diamond wire. The number of diamond particles on 10 m/min, 0.4 mm length and 65 μm bus was 60, which was about 30% of that on electroless nickel-plated diamond. Metal nickel layer can be deposited on the diamond by vacuum plating and can be used in the production of electroplated diamond wire.