Abstract: The continuous annealing and galvanizing simulator was used to study the anti-corrosion property and anti-corrosion mechanism Zn-Al-Mg alloy coatings. The results showed that the Zn-Al-Mg-RE alloy coating possesses good anti-corrosion property, Mg is the key factor which influences the microstructure and ingredient of Zn-Al-Mg series alloy coatings. Rare earth can improve the distribution of Mg in coatings.