As a common probiotic, lactic acid bacteria must be able to withstand gastric acidity and intestinal bile salts and survive in the human body in large amounts. Nowadays, most studies concerning the mechanism of acid resistance of lactic acid bacteria are focused on the theory of proton pump and alkali production. In addition, the contents of exogenous substances such as glucose, amino acid and fatty acid have a certain effect on its tolerance. The mechanism of inhibition lactic acid bacteria under bile salt stress mainly involves bile salt hydrolase, stress protein and the self-protection ability of its cell membrane. This article reviews the existing literature on the mechanism of acid and bile salt resistance of lactic acid bacteria. The second aim of this review is to explore the factors affecting the acid and bile salt resistance of lactic acid bacteria.