Gastrointestinal cancer has brought serious harm to the life and health of our people. Based on the characteristics of people-oriented and overall regulation, traditional Chinese medicine occupies a place in the prevention and treatment system of gastrointestinal tumors in China. Modern Chinese medicine has formed the concept of spleen strengthening as the core of prevention and treatment, but the understanding of spleen deficiency connotation is not unified among doctors. The application of prescriptions and medicines are quite different, which restricts the improvement of the quality of Chinese medicine research and the future development. Over the years, our team has achieved good results in the clinical and scientific research work of treating colorectal cancer from spleen deficiency, and has carried out evidence-based research on spleen deficiency in the field of gastrointestinal cancer with many domestic units. Based on the literature and the practice of the team for many years, this paper proposes that the pathogenesis of gastrointestinal malignant tumor is spleen deficiency. And we follows the evolution law of spleen deficiency, pathogenic excess from inside and outside, accumulation of cancer toxin, long-term disease leading to kidney, healthy qi deficiency, pathogenic excess, and cancer toxin, the 3 levels of TCM understanding of the pathogenesis. Meanwhile, it has the characteristics of gastric cancer easy to yang and colon cancer easy to cold . Finally, the paper lists the current relevant research practice from the rule of syndrome differentiation and treatment, clinical trials and biological mechanism. The paper has played an important role in exploring the theory of gastrointestinal tumors with spleen deficiency, and aims to promote the original innovation of the theory of TCM tumor prevention and treatment, and provide theoretical support for higher-quality research.