The prediction of protein flexible region provided a theoretical basis of the relationship between the soybean protein interface function and the structural activity. The rigidity and flexibility of protein structure affected the engineering characteristics， nutritional properties and biological functions of proteins. The protein flexibility reflected the movement of the protein conformation， and functional properties, such as solubility， emulsifying properties and foaming properties. Meanwhile the protein flexibility determined the characteristics of flexible region and the interface structure, which explored the adsorption structure of soy protein rearrangement at the interface. It has had an important practical significance of soybean protein processing and flexible interface functionality.