Abstract: Professor Wu Mianhua, a renowned national traditional Chinese medicine (TCM) practitioner, proposed the "deficient qi and Kenang" theory based on the doctrines of "deficient qi" and "Kenang". This theory is applied to the pathogenesis analysis and clinical syndrome differentiation and treatment of brain tumors. It posits that the fundamental pathogenesis of brain tumors involves original qi deficiency, internal generation of deficient qi, intermingling of phlegm and blood stasis, and conglomeration of toxins into nest-like foci. The treatment strategy emphasizes reinforcing healthy qi, regulating qi, resolving phlegm, dispelling stasis, attacking toxins, dispersing nodules, and adjusting treatment according to disease stages. In the early stage, it is to support healthy qi and regulate qi to remove qi deficiency; in the middle stage, it is to dissipate phlegm and expel blood stasis to resolve pathological nests; in the late stage, it is to attack toxins and resolve masses to break up nest sac. Throughout the treatment, strictly adhere to the principle of "reinforcing healthy qi without retaining pathogens, and breaking accumulations without impairing healthy qi".