Soybean soluble dietary fiber (SSDF) was extracted from soy sauce residue and soybean meal. The influence of SSDF on the physicochemical stability and digestive characteristics of soybean oil body (SOB) lotion was investigated by taking the absolute value of Zeta potential, average particle size, peroxide value (POV value), thiobarbituric acid value (TBARS value) and fatty acid release rate (FFA) as characteristic parameters. The results showed that certain concentration of SSDF could effectively reduce the Zeta potential, average particle size, POV value, TBARS value of SOB lotion system, and significantly improve the physical and chemical stability of SOB lotion. In addition, in vitro simulated digestion experiments further showed that the introduction of SSDF can significantly reduce the FFA release rate of SOB emulsion, which effectively delayed the digestion process of lipids in the gastrointestinal tract. This study can provide theoretical basis and reference for the high-value utilization of soybean processing by- products such as soy sauce oil residue and soybean meal, which could improve the processing applicability of SOB, and develop new low-fat health foods containing SOB and SSDF.