Abstract: Chemical cross-linking is an important means to improve gelatin properties. The degree of cross-linking determines gelatin properties. In order to better evaluate the chemical cross-linking of gelatin, this paper classifies the chemical cross-linking of gelatin based on the current domestic research situation, and combines with modern instrumental analysis technology to sort out a series of methods to evaluate the degree of chemical cross-linking of gelatin. Through the research, it is found that the physical properties, chemical structure and biological properties of gelatin after cross-linking have changed obviously, and these differences also reflect the degree of cross-linking of gelatin.