During the hot dip process of the corrosion resistant alloy Ni 3Al on the surface of the steel, it involves the solidification from liquid to coating The cooling rate has great influence on the microstructure and the performance By means of molecular dynamics simulation technique, the solidification process of liquid alloy Ni 3Al has been performed The F S N body potentials have been adopted to describe the atomic interactions The structural features have been revealed with the pair distribution The variation of energy with the temperature and the relationship between the energy and the microstructure has also been studied It has been concluded that the cooling rates have important influence on the final structure of Ni 3Al The Ni 3Al becomes the glass state at the relatively high cooling rate(4×10 13 K·s -1 ), but crystallize out at the relatively low cooling rate(4×10 11 K·s -1 ) At the same cooling rate(4×1011 K·s -1 ), the Ni 3Al melts of which Al is more than Ni crystallize out