Magnesium and its alloys have great potential as absorbable biomaterials in clinical medicine, but their rapid corrosion might lead to implant failure. The purpose of this study was to prepare Poly-β-hydroxybutyrate (PHB) coating with drug on the surface of WE magnesium alloys using layer-by-layer self-assembly technique. The corrosion behavior of magnesium alloys with drug coating in simulated body fluid (SBF) was studied. The solution concentration and microstructure change during degradation process were observed. The effects of drug coating on tissue cells were investigated by cell migration, cytotoxicity and apoptosis. The results showed that the bioactive drug coating effectively reduced the corrosion rate of the samples in SBF, cytotoxicity, apoptosis, and promoted the migration of the cells.