In vitro erythrocyte expansion technology, as a crucial interdisciplinary field between regenerative medicine and transfusion medicine, primarily relies on inducing hematopoietic stem/progenitor cells to differentiate into the erythroid lineage in vitro, thereby achieving large-scale expansion of mature red blood cells. In transfusion therapy, this technology demonstrates significant clinical potential for managing rare blood type donations, chronic transfusion-dependent diseases (such as thalassemia and sickle cell anemia), and immunocomplex patients. Compared to traditional donated red blood cells, in vitro expanded red blood cells offer significant advantages in controllable sourcing, consistent quality, and immunological compatibility. This technology holds promise for effectively alleviating clinical challenges such as blood resource shortages and transfusion-related immune complications.