Micronutrients including trace elements and vitamins are substances that the human body needs in small quantities but are necessary to involve in normal physiological process of organism. Malignant tumor as a chronic wasting disease is one of the major challenges in today's world. Patients with malignant tumors is a high-risk group for malnutrition and the 2019 report of the Chinese Society of Nutritional Oncology CSNO shows that the incidence of malnutrition in China's tumor patients is as high as 58%. Nutritional support for malignant tumor patients during therapy has been generally recognized. However as a part of nutrients the importance of micronutrients in malignant tumor patients has not yet attracted widespread attention. Micronutrient deficiencies will affect tumor development make patients tolerance to antitumor therapy decreased increase adverse reactions negatively affect quality of life and shorten patient survival period. The practice of micronutrient supplementation is subject to much controversy and uncertainty due to factors such as tumor type treatment regimen and individual differences. Therefore this consensus organizes interdisciplinary collaboration among medical nutritional and nursing parties based on existing domestic and international studies demonstrates the impact of micronutrient deficiencies on patients with malignant tumors. We also summarize and recommend measurements assessments and supplementation treatments of micronutrient for malignant tumors patients which satisfy the nutritional needs.