Mg-Al layered double hydroxide (LDH) as a container, loaded with molybdate anions,were synthesized via the coprecipitation method. The resulting compounds were characterized by X-ray diffraction (XRD) and Raman spectra, respectively. The properties of the release of inhibitor and the inhibition mechanism were observed and analyzed by slow-release experiment. The SEM-EDS、ICP and N2 adsorption-desorption measurements demonstrated the excellent anion-exchange and adsorption capabilities for chloride ion . Polarization curves measurements showed that the filtrate as electrolyte exhibited a lower corrosion current density value due to the presence of MoO42-.The result was demonstrated that the released inhibitor can provide adequate corrosion protection, maintaining a corrosion current density at approximately 9.129A穋m-2 for magnesium alloy within 24h. The coatings containing 20% MoO42—LDH pigment keep excellent corrosion resistance by electrochemical impedance spectroscopy (EIS) during immersion in 3.5% NaCl solution.