This paper primarily investigates the performance of commercially applied zinc-nickel coatings. The chemical composition of the coatings, the surface morphology (three-dimensional) and cross-sectional profiles of the coatings, the phase structure, grain size, corrosion products, and the distribution of coating elements along the depth were analyzed using ICP optical emission spectrometry, scanning electron microscopy (SEM), optical profilometry, X-ray diffraction (XRD), and glow discharge optical emission spectroscopy (GDS), respectively. The elemental composition of the passivation film on the surface of the zinc-nickel coatings was analyzed using X-ray photoelectron spectroscopy (XPS). The electrochemical performance and corrosion resistance of the coatings were tested using an electrochemical workstation and a salt fog chamber, respectively.The results indicate that the nickel content in the coating is 12.9%. SEM observations of the coating surface show that it exhibits a continuous, raised island-like morphology. Cross-sectional analysis reveals that the coating thickness ranges from 13.9 to 18.5 μm, with relatively uneven thickness and numerous cracks present. Optical three-dimensional topography of the coating surface indicates that the highest point is nearly 3 μm and the lowest point is nearly −6 μm, demonstrating significant undulation on the coating surface. The coating phase is identified as a single γ-phase, with calculated grain size of 20.23 nm. The distribution of oxygen on the coating surface suggests the presence of oxide films of both zinc and nickel. Depth profiling of characteristic elements such as chromium (Cr) indicates that the passivation film thickness is approximately 135 nm. Sputtering analysis using XPS at different times shows that the passivation film is mainly composed of three layers: the outermost layer primarily consists of Cr2O3 and a small amount of ZnO; the middle layer contains Cr2O3, Cr, ZnO, and Ni; while the bottom layer comprises Cr, ZnO, and Ni.Electrochemical measurements indicate that the self-corrosion potential of the passivated zinc-nickel coating is −0.71 V, and the self-corrosion current is 0.47 A/cm2. Compared to pure zinc coatings, the corrosion resistance is significantly enhanced. Under neutral salt fog conditions, no red rust appeared after 2200 h of corrosion, with the primary corrosion product being Zn5(OH)8Cl2·H2O. The higher self-corrosion potential, lower self-corrosion current, and dense corrosion products collectively determine the excellent corrosion resistance of the zinc-nickel alloy coating.