Refeeding syndrome generally refers to the electrolyte metabolism disorder characterized by hypophosphatemia after the body re-ingestion of nutrients after a long period of hunger or malnutrition which adversely affects the heart liver respiratory system nervous system and muscular system leading to clinical complications and even death. For severely malnourished patients refeeding syndrome is a potentially fatal complication. The incidence of refeeding syndrome among hospitalized patients in different hospitals ranges from 0. 43% to 34% and among tumor patients receiving nutritional treatment the incidence of refeeding syndrome can be as high as about 25%. The pathogenesis pathological and physiological changes of refeeding syndrome are related to insulin resistance electrolyte transfer to cells and enhanced synthetic metabolism. Based on existing research and evidence combined with clinical experience this article summarizes and recommends the diagnosis and treatment of tumor patients with refeeding syndrome.