Malnutrition is a common complication of malignant tumor patients. 40-80% of tumor patients have different degrees of malnutrition, and malnutrition can make such patients’ tolerance and effectiveness of anti-tumor treatment such as surgery, chemotherapy and radiotherapy decrease, toxic side effects increase, body physical status decrease, organ function damage, low quality of life and shorten survival time. Therefore, it is very important to improve the nutritional status of tumor patients through nutritional support.