Soybean is widely grown worldwide due to its high protein and high lipid content, and it has also become the main source of feed materials and edible oil in the world. With the increasing population and changes in dietary habits, there is a growing global demand for soybean consumption. Improving soybean yield and quality is crucial for ensuring sustainable soybean production. Through the review of literatures, this article comprehensively reviews the composition, function and nutritional characteristics of soybean seed protein, and discusses the genetic factors that affect the main protein components in soybean seed. The genetic factors that influence soybean seed protein composition are also discussed. Furthermore, the future trends in breeding processing-specific varieties to promote the development of high-quality soybean industry are also explored.