Abstract: Soy protein is widely used in food due to its good nutritional value, but it suffers from poor stability, low solubility and bioavailability in the process of being utilized. Therefore, specific processing is needed to make soy protein into nanoparticles in order to increase its specific surface area and improve the surface modification ability, as well as to endow the nanoparticles with excellent properties for use as carriers. Currently, single preparation methods for soy protein nanoparticles such as thermally induced aggregation, covalent cross-linking, and anti-solvent methods have been reported, however, the practical scope and advantages and disadvantages of these methods have rarely been discussed. In this paper, we firstly discuss the structure and composition of soy protein, then summarize the different preparation methods of soy protein nanoparticles, including physical, chemical, enzymatic, and composite methods, and then compare and analyze the mechanism, advantages and disadvantages, and application scope of the different methods on the protein structure. In addition, this paper highlights the advantages of the composite method for soy protein nanoparticle preparation, which can overcome the limitations of a single method in optimizing the size, distribution, and functional properties of nanoparticles, and has significant advantages in emulsion construction and bioactive substance loading. This paper can provide a methodological reference for the efficient preparation of specific soy protein nanoparticles, provide a scientific basis for the functional development of soy protein and lay a theoretical foundation for its expanded application in the food field.