<p>Magnesium (Mg)-based alloys have been widely concerned in the field of dental applications for their good biodegradability and biocompatibility. But their uncontrollably rapid degradation rate and inadequate anti-infection activity after surgery limited its practical application. In this study, chlorhexidine gluconate (CHX) was loaded by polylactic acid (PLA) on the calcium phosphate coated AZ31 alloy (Ca-P/PLA/CHX) by water bath method to improve its corrosion resistance and antibacterial activity. The results showed that the main components of the inner Ca-P coatings were CaHPO₄ (DCPA), (Ca, Mg)₃(PO₄)₂ and Ca₁₀(PO₄)₆(OH)₂ (HA), PLA coating was anchored on the Ca-P coating, and CHX molecules form hydrogen bonds with the PLA, further enhancing the compactness of the coating. And the binding strength of Ca-P/PLA/CHX coating to the substrate reached ASTM 5B standard. The Ca-P/PLA/CHX coating had the lowest passive current density associated with breakdown potential (1.79 × 10⁻⁶ A·cm⁻²) and the highest charge transfer resistance (3.56 × 10⁴ Ω·cm²). Thus, the Ca-P/PLA/CHX coating acted as a physical barrier to reduce the degradation rate of AZ31 alloy with a corrosion inhibition efficiency of 98.73%. The antibacterial rates of the Ca-P/PLA/CHX coating against <i>E. coli</i> and <i>S. aureus</i> were 99.42% and 99.73%, respectively, exhibiting good antibacterial activity due to the addition of CHX by directly inactivating the attached bacteria, and the antibacterial effect against <i>E. coli</i> and <i>S. aureus</i> were still as high as 97.01 and 98.11% after immersing for 3 d. The obtained Ca-P/PLA/CHX coating provides a new preparation method for corrosion resistance and antibacterial coating on Mg alloys, promoting the application of Mg alloys as alveolar fixation devices.</p> Graphical Abstract