Soymilk, as a nutritious plant-based protein drink, is favored by consumers worldwide. However, its undesirable flavor often affects consumer acceptance and limits the marketing of soymilk products. In this review, we summarize recent advances in understanding the formation mechanism of flavor substances in soymilk and their interaction mechanism with proteins in soymilk, and recent progress in improving the flavor of soymilk while maintaining its nutritional value through biological methods such as developing lipoxygenase-free soybean varieties, enzymatic treatment, and microbial fermentation. Finally, we point out future research directions for improving the flavor of soymilk, with a view to providing a theoretical basis for the quality improvement and marketing of soymilk and its products and contributing to the development of the soybean product market in China.