Lactic acid bacteria (LAB), like other free-living microorganisms, are usually exposed to various environmental stress conditions in the course of microbial fermentation, food processing and storage, which include starvation stress, osmotic stress, and heat stress. Enhancement of stress resistance is considered an effective strategy for better cell growth and increased the yield of metabolites. Heat stress is probably the most common stress, which bacteria and other organisms are confronted in the natural world and industrial applications. Some studies had demonstrated that LAB from different habitats responded to a sudden increase in temperature by rapid changes in gene expression resulting in elevated levels of heat-shock proteins (HSPs). Under normal conditions, HSPs assist in receptor regulation, cytoskeleton stabilization, and protein folding, assembly, transport, degradation, and under heat stress these functions become especially important. In this paper, the tolerance mechanism of heat stress in LAB and heat stress reaction of different LAB were discussed in order to provide a theoretical reference for the study of the heat stress response mechanism in LAB and to facilitate the industrial application of LAB.