BackgroundPure magnesium-based ortho-implants have a number of advantages. However, vital parameters like degradation rate and biocompatibility still call for significant improvement.MethodsIn this study, poly (1,3-trimethylene carbonate) (PTMC) and polydopamine (PDA) bilayer and micro arc oxidation composite coatings were prepared successively on magnesium surface by immersion method and microarc oxidation. Its corrosion resistance and biocompatibility were evaluated byin vitrocorrosion tests, cellular compatibility experiments, andin vivoanimal experiments.ResultsIn vitroexperiments demonstrated that the composite coating provides excellent corrosion protection and biocompatibility. Animal studies demonstrated that the composite coating slowed the degradation of the implant and was not toxic to animal viscera.ConclusionIn conclusion, the inorganic-organic composite coating proposed in this study provided good corrosion resistance and enhanced biocompatibility for pure magnesium implants.The translational potential of this articleThe translational potential of this article is to develop an anti-corrosion composite coating on a pure magnesium surface and to verify the viability of its use in animal models. It is hoped to open up a new approach to the design of new degradable orthopedic magnesium-based implants.