Sepsis is defined as life-threating organ dysfunction caused by a dysregulated response to infection. Severe cases may develop into multiple organ dysfunction syndrome (MODS) and even death. However, conventional therapeutic intervention for sepsis is not ideal. Mesenchymal stem cells (MSCs) are multipotent stem cells that can differentiate into a variety of cell types. They are characterized by anti-inflammatory, anti-microbial, and immunomodulatory power, and rehabilitation of tissues and organs and anti-apoptosis. The role of MSCs in regulating immune function, regulating signal transduction pathways, repairing tissues and organs, and antibacterial and antiviral effects, is summarized in this review in order to understand the mechanism of application of MSCs in the field of sepsis, and lay the foundation for further research.