Soy proteins (SPs), as vital plant-based proteins, hold significant promise for applications in food and medicine. However, their functional properties are limited due to their complex structures, which often fail to meet practical requirements.. With advancements in modern processing technologies, diverse protein modification techniques have been extensively investigated. This article reviews the effects of physical, chemical, and biological modification technologies on the structural and functional properties of SPs. It explores the mechanisms by which structural modifications improve functional properties and summarizes the current research on enhancing SP properties through combined modification techniques. Future research should focus on expanding the application potential of SPs and advancing the soybean industry.