Foam dispersion systems have been widely used in the processing of various foods, which can impart good texture and sensory properties to food systems. This article describes the mechanism of the formation and stabilization of foam systems and foam microstructure. The influence mechanism of protein nano-polymers on the stability of foam systems is expounded from the perspective of particle size, net surface charge, morphology, and interface characteristics. This article also summarizes the preparation methods for protein nano-polymer and their advantages and disadvantages. This review aims to provide theoretical support for preparing protein nano-polymers for food systems with desirable foam texture and to promote the application of protein nano-polymers in foam-based foods.