Abstract: Protein nanoparticles are nano-sized protein particles. Compared with synthetic nanomaterials, protein nanoparticles have great advantages in the embedding and transmission of bioactive substances due to their good biocompatibility and biodegradability. In recent years, protein nanoparticles have gradually become a research hotspot. In this paper, the common types of animal protein nanoparticles and plant protein nanoparticles which are currently mainly used in food industry are firstly introduced, and the common preparation methods of protein nanoparticles are also summarized, including anti-solvent precipitation method, salting-out method, nano spray drying method, electrospray method, supercritical fluid method and thermally induced aggregation method. The mechanisms of various methods as well as their advantages and disadvantages in terms of safety, applicability, product quality and operation complexity are analyzed. In addition, the applications of protein nanoparticles in the production of functional foods, the active packaging of foods and the stabilization of food Pickering emulsions are reviewed. Finally, the research status on application safety of protein nanoparticles is concluded. It is hoped to provide theoretical reference for further research on protein nanoparticles.