Abstract: Based on a hot-dip galvanized CR3 sheet with a Zn-1.5%Al-1.5%Mg zinc-aluminum-magnesium coating (CR3-ZM70) and a pure zinc-coated CR3 sheet (CR3-Z70), the coating phasesare analyzed and the forming performance, weldability, paintability, adhesion properties, and corrosion resistance in service are experimentally analyzed. The feasibility of replacing pure zinc-coated sheets with Zn-Al-Mg-coated sheets in automotive body applications is assessed. The results demonstrate that the Zn-Al-Mg coating consists of pure zinc, zinc-magnesium binary, and zinc-aluminum-magnesium ternary phases, with all phase grain sizes 50 μm or small and significantly smaller than those of the pure zinc coating. The addition of Al and Mg increases surface oxide formation on the Zn-Al-Mg coating. Its nano-hardness exceeds that of pure zinc coating by over 33%. The surface friction coefficient of CR3-ZM70 is 27% lower than CR3-Z70, and it exhibits better friction stability after repeated tests. CR3-ZM70 shows 72% less stamping scale-off compared to CR3-Z70. The welding current window width and nugget size are comparable between the two coatings. Both achieve equivalent electrocoating performance, with phosphating film grain sizes 10 μm or small. However, CR3-ZM70 exhibits lower cohesive fracture performance in some structural adhesives and spot welding pastes. Under identical neutral salt spray conditions, CR3-ZM70 demonstrates three times the corrosion resistance of CR3-Z70, with significantly better cyclic corrosion resistance in post-electrocoating exposed substrate tests. The experimental results confirm that Zn-Al-Mg-coated sheets outperform pure zinc-coated sheets in forming performance and corrosion resistance, while showing comparable weldability and paintability. However, their adhesion property is inferior to that of pure zinc-coated sheets. Thus, Zn-Al-Mg coatings are viable substitutes for automotive body applications but cannot fully replace pure zinc coatings.