Abstract: This paper introduces an innovative physical and chemical design experimen,and attempts to use the “maximum bubble pressure” method of basic physical chemistry to investigate the change law of the physical and chemical properties of gelatin solution at isoelectric point,and then expand the experimental method for measuring the isoelectric point of gelatin solution.The results show that the surface tension of gelatin solution changes obviously at the isoelectric point.The variation trend of the surface tension of the gelatin solution by the maximum bubble pressure method can preliminarily determine the range of the isoelectric point of the gelatin.The design of this experiment can improve students' ability to integrate their knowledge and experimental techniques and enrich the contents of basic physical chemistry experiment teaching.