Sarcopenia is a syndrome characterized by progressive and generalized skeletal muscle loss and hypofunction. Cancer patients have a higher incidence of sarcopenia due to hypercatabolic and low anabolic states. This sarcopenia associated with malignant tumors, called cancer⁃related sarcopenia, which not only affects the normal metabolism of body components in patients, but also reduces the efficacy of treatment, quality of life and survival of patients. Therefore, it has far⁃reaching significance for the long⁃term survival of patients to do a good job in nutritional screening and evaluation of cancer patients, timely detection of cancer⁃related sarcopenia, and effective intervention for the long⁃term survival of patients. Based on this, the Chinese Society for Nutritional Oncology organized experts to formulate this consensus, which contents mainly based on the current Chinese cancer⁃related sarcopenia diagnosis and treatment status, evidence published at home and abroad, combined with the experience and opinions of experts in the fields of clinical, pharmaceutical, nutrition, nursing, etc., used the European Society of Cardiology (ESC) evidence grading and recommendation intensity standards, and focused on the screening, diagnosis, evaluation, treatment of malignant cancer⁃related sarcopenia for analysis, discussion and summary. Finally, the clinical diagnosis and treatment guidelines for cancer⁃related sarcopenia were formulated for clinicians to provide a reference basis for standardized diagnosis and treatment.