With the wide application of hot-dip steel, corrosion of hot-dip equipment in liquid metal and reduction of steel surface quality caused by it become gradually prominent, which limit the sustainable development of hot dipping industry. In this paper, corrosion behaviors of iron-based, cobalt-based and other alloys in hot-dip molten Galvalume (Zn-55Al-1.6Si%) alloy were discussed. The main factors for alloy’s failure are the dissolution of the alloy and its corrosion product, the mutual elements diffusion and the growth stress concentration in corrosion layer. To enhance corrosion resistance of materials in liquid Zn-Al alloy, various protective methods, such as alloying of metals and applying of protective coating were proposed. The influence of different alloying elements on the corrosion behavior of alloys was reviewed, and the protective effects of ceramic coatings, metal-ceramic coatings and enamel coatings in the condition were evaluated. The boride alloyed in substrate or in coating can effectively reduce the corrosion in the liquid Zn-Al alloy, of which its main mechanism is raising the non-wettability in liquid metal. Finally, the designing principles for high-performance protective coatings and alloys, as well as their failure mechanism in molten Galvalume alloy are prospected and summarized.