Abstract: Copper-nickel (Cu-Ni) alloy coatings were prepared on Q235 carbon steel substrate by electrodeposition method using choline chloride-ethylene glycol room temperature ionic liquid as the electrolyte solvent. By analyzing the cyclic voltammetry curves of electrolytes from each system, the co-deposition mechanism of metal ions in the electrodeposition process was determined. The results show that the co-deposition of Cu and Ni is easy to achieve in this system. The effects of the current density variation on the micro-morphology of the coating and the corrosion resistance of the coating were investigated. The results indicate that the nickel content in the plated layer increase with the increase in current density, and the grain morphology of the plated layer also changes significantly with the change in current density. When the current density increases from ‒1.5 mA/cm² to ‒4.0 mA/cm², the corrosion resistance of the coating increases first and then decreases, and when the current density is ‒3.0 mA/cm², the corrosion resistance of the obtained coating is optimal.