Abstract: In this study, the process parameters of ultrasonic pretreatment-assisted chicken soup preparation were optimized using the response surface method, and the effects of ultrasonic pretreatment on nutrient migration and micro-nano particles (MNPs) formation during stewing were investigated to improve the nutrient content and storage stability of chicken soup. The optimum conditions for ultrasonic pretreatment of chicken soup were temperature 50 ℃, time 20 min, power 830 W. Under these conditions, the contents of solids, protein, amino acid nitrogen, total sugar, and total lipid in chicken broth increased by 35.13%, 26.09%, 33.47%, 21.59% and 44.04%, respectively. During MNPs formation, particle size and polydispersity index decreased to 322.27 nm and 0.47, respectively, and the absolute value of the zeta potential increased significantly (P<0.05). In addition, ultrasonic pretreatment induced changes in the protein secondary structure of MNPs, reducing α-helices and converting to β-folding and protein solubility to 87.40%, thereby improving chicken soup stability. These results demonstrate the potential application of ultrasonic pretreatment technology in producing high-quality chicken soup.