According to the electrochemical corrosion principle of zinc-aluminum alloy coating， combined with the data of coating microstructure test， uniformity test， and neutral salt spray corrosion test， a two-dimensional corrosion cellular automaton model of zinc-aluminum alloy coating was developed， and the corrosion process of zinc-aluminum alloy coating was simulated. Then， the influence of the coating metal oxidation， the coating metal hydration， the hydrate dissolution， and the coating non-uniformity on the corrosion process were analyzed. The research results indicate that the two-dimensional corrosion cellular automata model can accurately simulate the corrosion process of zinc-aluminum alloy coatings. During the coating corrosion， metal oxidation plays a leading role， and metal hydration and metal hydrate dissolution are secondary factors. At the same time， the oxidation probability is nonlinearly proportional to the amount of metal corrosion per unit area， the dissolution probability is nonlinearly proportional to the amount of metal corrosion per unit area， and the hydration probability is inversely proportional to the amount of metal corrosion per unit area. The uneven distribution of metal content in the coating has little effect on the coating corrosion process， but the coating uneven thickness leads to premature corrosion of the iron matrix in local areas， resulting in the appearance of pitting pits.