The effects of protein fibrillation modifications on foam properties and the foaming and stabilization ability of soy protein fibrils (SPF) and chitin nanowhisker (CNW) complex systems were investigated and evaluated. The results showed that the structure of SPF stretched significantly with the increase of heating time, probably due to the unfolding and rearrangement of protein structure. The foaming ability and stability of SPF were significantly higher than those of natural protein. The SPF and CNW coacervates effectively increased the foam strength, probably due to the interaction between the “worm-like” SPF structure and the short crystal structure of CNW. In addition, the samples containing salt had higher foaming ability, stability and viscosity compared to those without salt, resulting in a significant improvement in foaming properties. This study provided a new idea for studying the functional properties of modified protein-modified polysaccharides complex coacervates.