In order to effectively solve the problem of bacterial infection and the release of harmful metal ions after long-term implantation of biomedical titanium alloys in the human body, Graphene oxide coating (GP/T) and Graphene oxide/Nano-zinc oxide composite coating (GZP/T) were prepared on the surface of Ti6Al4V alloy pretreated by Polydopamine(PDA) respectively with hydrothermal reaction and coating methods. The phase structure, microstructure, corrosion properties in Ringer"s solution and antibacterial properties in Escherichia coli environment of the two coatings were systematically analyzed. The results show that Polydopamine plays the role of "double-sided tape" bridging and effectively enhances the chemical bond between the coating and the substrate. The antibacterial rate of GP/T coating increased with GO concentration increasing. The GZP/T nanocomposite coating has superior corrosion resistance compared with Ti6Al4V substrates, and the ZnO in the composite coating plays a major antibacterial effect.