When it comes to the prognosis of oncology patients, we often hear that 1/3 of patients die of fright, 1/3 of patients die of starvation (studies report that about 20% of malignant tumor patients die as a direct result of malnutrition), and 1/3 of patients die of treatment. It can be seen that good mind, nutritional support has a direct impact on treatment outcome and prognosis. Malnutrition is a common complication of malignant tumor patients, about 40-80% of tumor patients have malnutrition, which causes the decrease of tolerance and effectiveness of anti-tumor therapy surgery, chemotherapy and radiotherapy, increase of toxic effects, decrease of body physical status, damage of organ function, low quality of life and shorten of survival time. Thus, psychological guidance to patients and improvement of nutritional status of tumor patients through nutritional support has a crucial role. In clinical nutritional support for malignant tumor patients, medical and nursing staff and patients and families should pay attention to the following points: 1. Do not turn a blind eye to malnutrition, considering malnutrition as an inevitable complication of malignant tumor patients, or even cachexia in the state of surgery, chemotherapy, radiotherapy, etc. The anti-tumor treatment such as radiotherapy, so that the efficacy of the treatment is poor and the toxic side effects increase. Therefore, malnutrition should be taken seriously and treated actively, instead of being regarded as the inevitable state of tumor patients and allowed to develop. 2. In the late palliative treatment stage, adjustment of mind, Chinese medicine treatment and nutritional support can enable patients to maintain their daily home life and improve their quality of life. The main purpose and principle of treatment at this time is not to cure cancer, but to improve organ function and immune status through supportive treatment, reduce toxic side effects caused by anti-tumor treatment and alleviate pain, thus playing a role in improving patients’ prognosis. 3. Like other treatment methods, supportive therapy should be used as early as possible to maximize its effect. However, the timing of nutritional support is usually late, most of them are already cachectic or end-stage, and the use of nutritional support is only considered when all antitumor treatments have ended or cannot be continued. The current problem is that many medical personnel and patients’ families resist to take oral nutrition, nutrients, micronutrients, protein powder, thinking that they are cheating. Many tumor patients who should be on nutritional support cannot be on nutritional support in time because nutrition is not taken seriously, and the efficacy is affected. What’s more, the occurrence of some tumors is itself related to the long-term insufficient intake of some trace elements, and the human immune system needs sufficient nutrients to maintain normal functions, just like the heart and liver. Therefore, I believe that prospective and preventive nutritional support therapy must be carried out for tumor patients. 4. Since most tumor patients have decreased immune function, they are at high risk for vena cava catheter infection and morbidity. When the gastrointestinal tract is functional, the way of nutritional support should be preferred to enteral nutritional support route. The advantages of this way are conforming to physiology, protecting the barrier function of gastrointestinal tract, inexpensive and easy to use. Oral adjuvant nutritional preparations between normal meals in a calm mood can help the recovery of patients undergoing surgery, chemotherapy, radiotherapy, and taking herbal medicine. If the nutritional needs of the organism cannot be met, enteral nutritional support through nasogastric tube and percutaneous endoscopic gastrostomy/jejunostomy is still a good method. Parenteral nutritional support is adapted for use in patients with short bowel syndrome, radiation enteritis, and intestinal obstruction. According to the different disease states, choose the reasonable way, both parenteral and enteral nutrition support are very good methods. 5. The consideration of nutritional supplementation in oncology patients is mostly limited to dietary advice and encouragement of oral feeding, but rarely actively at the level of enteral and parenteral nutritional support, and very well designed nutritional therapy programs. There have been many studies showing that reasonable and timely nutritional support treatment in oncology patients can reduce the number of complications and shorten the hospitalization days, which can save many treatment costs and obtain a better price-to-benefit ratio. 6. Clinical studies have no positive evidence that nutritional support has an enhancing effect on tumor growth. In recent years, some special immune nutrients such as polysaccharides and N-3 fatty acids have been found to inhibit inflammatory response and enhance immune function, and some studies have found that they have the effect of inhibiting tumor growth.