Abstract: To insure Lactobacillus acidophilus against mechanical compression and gastric acid, successfully reach the intestine to act the role of probiotic.,this paper adopted porous starch as wall material to microencapsulate Lactobacillus acidophilus. Through the single factor experiment and orthogonal experiment, four factors that influenced microencapsulation such as pH value, oscillation time, porous starch dosage and temperature had been analysised. The results show that: the porous starch dosage of 5 g, pH 6.0, temperature 20 ℃, concussion 200 r/min 50 min, the embedding rate is 67.12 %.This is the optimum technological conditions of Lactobacillus acidophilus microencapsulation. According to detecting the change of Bifidobacterium, Lactobacillus, Escherichia coli, Clostridium perfringens in quantity and pH value of canine fecal, which is obtained from puppies after fed the preparation of microencapsulation of Lactobacillus acidophilus, which can effectively improve the dog gut microflora.