Abstract: Umbilical cord mesenchymal stem cells are multidirectional stem cells from the umbilical cord that can inhibit tumor development through exosomes. Exosomes secreted by umbilical cord mesenchymal stem cells play an anti-tumor role by participating in immune response, inhibiting tumor cell proliferation, reducing angiogenesis and improving drug sensitivity. However, there are few studies on the application of exosomes secreted by umbilical cord mesenchymal stem cells in tumor therapy. The paper reviewed the mechanism of action and application prospect of these drugs in tumor therapy.