Abstract: Using graphene quantum dots with unique properties as the second phase additive, Ni-based nanocomposite coatings were prepared by supercritical pulse electrodeposition technology. The effects of current density on the microstructure, corrosion resistance and mechanical properties of coatings under supercritical conditions were investigated.The results show that when the current density is 6 A·dm^-2, the microstructure of the prepared coating is uniform and densified, and it shows better sphericity. Raman spectroscopy detection shows that supercritical pulsed electrodeposition can improve the quality of graphene quantum dots. When the current density is 6 A·dm^-2, the corrosion resistance and mechanical properties of the prepared coating are more excellent, its capacitive arc radius is the largest, the capacitive modulus is the largest, and the corrosion current density is smallest. Its corrosion current density is only 52%, 62% and 29% of the coatings prepared at current densities of 3, 4.5 and 9 A·dm^-2. Its microhardness is the highest, reaching 837.6 HV0.2, and the friction coefficient and wear scar cross-sectional area are the smallest, showing the best wear resistance.