In order to improve the gastric fluid tolerance and storage stability of Lactobacillus acidophilus JYLA-126， a probiotic microcapsule delivery system was constructed by endogenous emulsification using soybean whey protein (SWP)-sodium alginate as the composite system as the wall material. The process parameters were optimized by one-way and response surface tests， and the optimal preparation conditions were determined as follows: sodium alginate mass fraction of 2%， sodium alginate to calcium carbonate mass ratio of 1∶2， sodium alginate to soybean whey protein volume ratio of 1∶1， water to oil volume ratio of 1∶3. The embedding rate of Lactobacillus acidophilus JYLA-126 microcapsules under this process condition was 72.12%， and the microcapsules had good acid resistance and enteric stability， and were suitable for storage at 4 ℃. The results showed that the microencapsulation system could effectively improve the survival rate of Lactobacillus acidophilus in gastrointestinal transit and long-term storage stability， which provides a new strategy for the development of environmentally friendly and low-cost probiotic targeted delivery system.