Cancer therapy-related thrombopenia,which is called"medicinal poison purpura"in tradi-tional Chinese medicine,is a common hematologic adverse reaction during oncology treatment that is dif-ficult to treat due to the differences in oncology treatments and the complexity of the pathogenesis,resul-ting in various degrees of thrombocytopenia.Based on the theory that"spleen controlling blood",this pa-per believes that"medicinal poison purpura"is mainly caused by direct damage to the blood and qi by medicinal poison,leading to qi and blood deficiency;it also attacks the spleen and stomach,resulting in the deficiency of spleen qi and no source of qi and blood production.Due to the spleen deficiency,there is no essence to nourish kidney and bone marrow;their function of generating blood decreases,eventually it becomes"medicinal poison purpura".The theory of"regulating balance and flat regulation"is an im-portant academic idea of our team in the treatment of malignant hematological tumors.In this paper,we have systematically elaborated on the etiology,pathogenesis,and therapeutic principles of the treatment of cancer therapy-related thrombopenia with spleen deficiency pattern through the collation of relevant lit-erature.We believe that the prescription formulated according to the method of invigorating spleen and benefiting qi and controlling blood for the treatment of cancer therapy-associated thrombocytopenia with spleen deficiency pattern is in line with the principle of correspondence between prescription and syn-drome,and correspondence between drugs and syndrome in traditional Chinese medicine,which is theo-retically feasible and has a high clinical application value.