Lactiplantibacillus plantarum is a type of gram-positive bacterium widely found in nature, especially in fermented foods, such as kimchi, fermented meats, dairy products, and wine. L. plantarum has been shown to colonize the intestinal tract of humans and other mammals, while also exhibiting substantial health-promoting effects. In terms of probiotic functions, L. plantarum has demonstrated multidimensional health effects, including intestinal homeostasis, cognitive improvement, cholesterol reduction, and inflammation relief via modulation of gut microbial structure, enhanced intestinal barrier function, neurotransmitter regulation, and immune-signaling activation. However, the activity and effects of L. plantarum are influenced by various environmental stresses, including acidity, bile salts, osmolality, temperature, and oxygen levels. L. plantarum employs various stress tolerance mechanisms, including active proton efflux systems, bile salt hydrolase-mediated catalytic hydrolysis, and the dynamic balance of compatible solutes, to ensure its survival and functional stability in extreme environments. Therefore, this review systematically integrates advances in domestic and international research, focusing on the probiotic function and stress-resistance mechanisms of L. plantarum. In addition, it outlines the potential application value of multi-omics technologies for in-depth analysis of the environmental adaptability of this species. These findings provide a theoretical basis for developing functional strains and designing precise probiotic formulations.