Analysis of the results of studying cathodic polarization curves and the influence of deposition regimes on the cathode-current efficiency, fine structure, cross-sectional growth structure, microhardness and wear resistance of composite nickel coatings makes it possible to establish program-controlled current modes (density of variable steps of electric current, as well as their duration), during which the formation of microlayered structures of composite nickel coatings with an increased content of nanodiamond particles (2.6% wt.) and a microlayer thickness of < 1 μm is observed. As shown, the variable DC steps with a density from the maximum allowable quality of the deposited coating to the maximum on diffusion allow both increasing the microhardness and wear resistance of coatings and increasing the rate of their deposition. The kinetics of nucleation and growth of composite nickel coatings obtained by program-controlled current are studied. With an increase in cathode overpotential from 0.97 V to 1.26 V and with an increase in current density from 100 A/m² to 500 A/m², the nucleation rate of crystalline nuclei increases by 1.3–1.7 times, and the growth rate increases by 2.5–3.0 times. Composite nickel coatings become more finely crystalline, as evidenced by a decrease in the size of mosaic blocks from 96 nm to 65 nm.