Abstract: In order to improve the weakness of acid and oxygen intolerance,the method for the preparation of Bifidobacterium microcapsules was established. Calcium alginate hydrogel was formed by sodium alginate and calcium chloride,and then it combined with chitosan to form polyelectrolyte membrane. The preparation process of Bifidobacterium mixed gel microcapsule was optimized by single factor and Box-Behnke response surface test,and the structure of the microcapsule was observed by scanning electron microscopy,and the release characteristics and survival rate of Bifidobacterium in the microcapsule were investigated by simulated gastric juice and intestinal juice independent influence experiment and simulated human continuous digestive tract experiment. Results showed that the centrifuge Bifidobacterium was uniformly mixed with sodium alginate with a mass fraction of 1.5%,injected into calcium chloride solution with a mass fraction of 1.2%,and then immobilized with chitosan with a mass fraction of 0.5% for 35 min. Under these conditions,the appearance and shape of the capsules were intact,and scanning electron microscopy showed that the microcapsules had compact structure and good embedding performance. The gastrointestinal release experiment proved that the capsules had the characteristics of slow-release carrier that was dissolved in the intestinal tract and insoluble in the stomach. The average survival rate of Bifidobacterium in the capsules in intestinal fluid was 72.3%,and the average survival rate after simulated human digestive tract treatment was 49.8%. The results would provide a reference for microencapsulation of Bifidobacterium.