Abstract: Patients with cancer are at high risk of malnutrition, which is the most common complication and independent risk factor for death in cancer patients. This article elaborates on the creation and structure of the diagnostic and treatment systems for cancer malnutrition in China, as well as the process from the initial understanding to the gradual establishment and continuous innovative development of the these systems. It briefly describes the commonly used methods for cancer nutrition screening and assessment in clinical practice at present and introduces the new methods in clinical application in recent years. The aim is to provide reference basis for further optimizing this diagnostic and treatment system, thereby improving the diagnosis and treatment level of cancer malnutrition in China, thus, enhancing the prognosis of patients and reducing the medical expenses.