The invention belongs to the field of 
biotechnology, and relates to 
Lactobacillus acidophilus and application thereof and a 
feed additive thereof and a premix compound thereof. The 
Lactobacillus acidophilus of the invention has strong stress tolerance, and can tolerate simulated 
gastric fluid and simulated bile salt so as to guarantee that a great quantity of viable 
bacteria can smoothly enter the intestinal tract of an animal, and the viable 
bacteria play a 
probiotic role, so that the 
immunity of the animal is improved, and the breeding cost is reduced. The product obtained from the 
Lactobacillus acidophilus of the invention through culture, high-density 
fermentation and addition of protectant has a high content of viable 
Lactobacillus acidophilus, can be added as a biological 
feed additive in the drinking water or feed for breeding animals, and can be prepared into feed such as premix compound and so on, so as to reduce the addition of 
antibiotics, indeed improve the intestinal tract health and the 
immunity of animals, and increase the production performance of animals.