With the deepening research on the immune mechanisms of malignant tumors the study and clinical application of immunonutrients are continually advancing and innovating. A multitude of studies have shown that various immunonutrients can prevent the occurrence of malignant tumors reduce resistance to certain chemotherapeutic drugs alleviate postoperative complications shorten hospital stays and expedite recovery of immune function and nutritional status through mechanisms such as anti - inflammation enhancement of immune cell functions inhibition of malignant tumor cell proliferation and metastasis as well as induction of tumor cell apoptosis. However despite this extensive research there is currently no consensus on the preventive therapeutic and prognostic roles of immunonutrients like glutamine arginine ω-3 polyunsaturated fatty acids and vitamins in the context of malignant tumors due to the scarcity of large-scale high-quality evidence. This article aims to systematically review the mechanistic roles and clinical efficacies of protein-based immunonutrients glutamine and arginine fatty acid-based immunonutrients ω-3 polyunsaturated fatty acids micronutrients vitamins and selenium microecological immunonutrients synbiotics and plant extract - based immunonutrients ginsenosides in the context of malignant tumor prevention and management. The objective is to explore the distinct features and inherent limitations of these different categories of immunonutrients thereby providing a foundation and direction for further in-depth research on the use of immunonutrients against malignant tumors and their integration into clinical practice.