Abstract: In biomolecular interaction studies and protein purification experiments,the quality of the experimental sample solu-tion,protein purity and homogeneity have been the key factors determining the final experimental results. In this paper,the dynamic light scattering technique is used to measure the slope of the autocorrelation function curve of the molecules in the solution sample,an-alyze the particle size distribution,analyze the influencing factors of the sample solution quality,and optimize the experimental scheme. The experimental results show that the dynamic light scattering technique provided an effective experimental basis for the opti-mization of conditions in molecular biology experimental research,greatly improved the purity of the protein after purification experi-ments and improved the quality of experimental data in the study of biomolecular interactions.