The application relates to a preparation method of a
magnesium alloy stent composite coating and belongs to the technical field of biomedical materials. In view of the technical problem that an existing
polyester coating produces acid by degradation, and accelerates
corrosion of a
magnesium alloy stent, a
composite coating with piezoelectric-pH synergistic protection function is provided. The
coating comprises a PVDF-g-APTES primer layer, a pH regulating intermediate layer composed of PVDF, PDLLA and alkaline nanoparticles, and a
drug-loaded PDLLA outer
coating. The application actively increases the interface pH to the
passivation zone by on-demand release of alkaline nanoparticles, and realizes the
positive feedback mechanism of "the more stress, the more protection" by using the piezoelectric effect. Compared with the prior art, the dynamic
corrosion resistance of the application is increased by more than 40%, the synergistic effect makes the protection effect increased by more than 60%, the
piezoelectricity and
alkalinity are synergistically protected, a long-acting
corrosion-resistant and intelligent response comprehensive solution is provided for the degradable
magnesium alloy implant device.