Weight loss of patients after chemotherapy is a relatively common phenomenon among tumor patients. The reasons for weight loss after chemotherapy are many, 1, chemotherapy drugs kill tumor cells at the same time, the normal cells and tissues of the body will also cause damage to the gastrointestinal function will also have an impact. During the period of chemotherapy, patients are prone to the clinical manifestation of decreased appetite and insufficient nutritional intake.2. Tumor tissues consume a large amount of protein and other nutrients, and after chemotherapy, patients have the clinical manifestation of decreased diet, resulting in insufficient intake and excessive consumption, which leads to the weight loss of the patients.3. After learning that the patients are suffering from the tumor, the patients’ spirit is subjected to a great blow, which also results in the influence of the patient’s diet and leads to the insufficient intake of nutrients, and the patients’ diet is affected, which leads to the insufficiency of nutrients. This will lead to insufficient nutrient intake and weight loss. After the emergence of this symptom, it is necessary to strengthen the patient’s psychological guidance, and at the same time, strengthen the nutritional support treatment, so as to help the patient through the discomfort period of chemotherapy.