The process and recovery of allogeneic hematopoietic stem cell transplantation are closely related to the immune system. Current research shows that in addition to the immune organs such as the spleen， thymus， and bone marrow， tissues such as the small intestine and liver also play an important role in immune regulation. The interaction of the intestine-liver axis， liver-spleen axis and other organs in immune regulation supports a better view to understand the mechanism of disease development and to develop immune related therapy methods. Our team applied the dual-protein to the clinical nutrition intervention of allogeneic hematopoietic stem cell transplantation， and found that the dual-protein can significantly promote immune reconstruction， shorten the average transplantation time， and conduct a preliminary exploration of its mechanism. In this paper， a review about the immune interaction mechanism among intestine， liver and spleen is performed， which followed by a new concept of intestine-liver-spleen axis （ILS Axis） and its mechanism. A hypothesis is proposed that dual-protein promotes hematopoietic and immune reconstruction， and therefore accelerates patient recovery via intestine-liver-spleen axis based on the results of dual-protein clinical trials and animal experiments.