Objective To enhance the bonding strength between the diamond and the substrate. Methods The diamond was pretreated with a method of " degreasing—roughening—sensitizing activation—glue", and then surface was modified by electroless nickel plating on the diamond. The influence of different parameters on chemical plated nickel layer was studied by scanning electron microscopy and energy dispersive X-ray. Results The optimum technical parameters of nickel layer on the diamond about 10 microns: NiSO4·6H2O (main salt) 25 g/ L, hypophosphite 30 g/ L, lactic acid 15 g/ L, sodium acetate 15 g/ L, the stabilizer 20 mg/ L, brightener 1 g/ L, pH=5. 5, temperature 85 ℃. Conclusion Hypophosphite content, thiourea content, pH, and temperature may affects the plating time, the diamond coating weight gain ratio and morphology of chemical nickel. The diamond was coated complete uniform with the optimal parameters.