In order to provide a theoretical premise for the purification of soy oligosaccharides from soybean whey, this paper examines the yeast PL08 fermentation process for purifying functional soybean oligosaccharides. Using the logistic model and the Luedeking-Piret model, the kinetics of PL08 cell growth, sucrose consumption, and ethanol production were determined by nonlinear data fitting. The linearity of the models was as high as 0.98, indicating the viability of this method. At 30h, the batch fermentation procedure revealed that the purity of functional oligosaccharides was 94.12%, while the ethanol concentration continued to rise to 3.0%vol. Based on the results of kinetic studies, a 10L exponential feeding culture was conducted, and the results indicated that the alcohol concentration can be controlled below 0.10%vol, the maximum biomass concentration was 50.01g/L, and the maximum purity of functional soybean oligosaccharides was 95.59% in 21h.