Aiming at enhancing the antibacterial property of biomedical magnesium alloy with hydroxyapatite coating, silver-copper-codoped hydroxyapatite (AgCuHA) biomimetic coating was prepared on chitosan interlayer. XRD, SEM, EDS, TEM, optical profiler and contact angle tester were applied to analyze the phase, surface morphology, chemical composition, crystal structure, surface roughness and hydrophilicity of the coatings. Spread plate and CCK-8 methods were adopted to test antibacterial property and cell viability of the coatings. The results indicated that AgCuHA coating was constructed by nanodefect-rich nanocones in a bottom-up way, resulting in a kind of biomimetic micro/nano-topography. This hydrophilic biomimetic coating not only showed high antibacterial property, but also inhibited magnesium alloy rapid degradation and demonstrated good cytocompatibility.