Using Lactobacillus casei, Lactobacillus fermentum, and Saccharomyces cerevisiae to ferment soybean syrup water, the viable lactic acid bacteria and yeast were used as indicators to study the effect of molasses addition, initial pH, inoculation amount, inoculation ratio, culture speed, fermentation temperature and time on the number of viable bacteria in fermentation broth. On the basis of single factor experiment, the response surface method was used to optimize the technological parameters of soybean yellow slurry fermentation. The results showed that the best process parameters were: inoculation amount 6%, inoculation ratio 1∶1∶1, culture speed 120 r/min, culture time 2 days, molasses addition 5.12%, initial pH 6.80, culture temperature 30.97 ℃, under which thenumber of viable lactic acid bacteria in the fermentation broth of soybean yellow jelly was 3.18×109 CFU/mL, and the number of yeast was 4.1×108 CFU/mL.