Molecular machine is a kind of machine composed of molecular scale materials and can perform a certain processing function. Three-dimensional structure determines the related properties and functions of proteins. How the amino acid （residue） sequence of a protein folds into a specific three-dimensional structure， that is， understanding the folding mechanism and characteristics of protein structure is of great significance for the study of molecular machines. Therefore， it is necessary to use a fast and simple simulation method to study the folding mechanism information of protein structure. In this paper， based on the natural state topology of protein， we use Gaussian network model to study protein GB1 and analyze the structural characteristics of protein GB1 and its unfolding process. The results are in good agreement with experimental data and molecular dynamics simulation data， showing that the elastic network model is suitable for the study of protein structure.