Abnormal nutrition metabolism and immune imbalance permeate the entire process of tumorigenesis and development. In tumor immunotherapy immune checkpoint molecules enable tumor cells to achieve immune escape. Although T cell-based immune checkpoint inhibitor therapy is effective it faces the problems of low clinical response rate and severe side effects. Currently nutritional therapy has been recommended as a first - line treatment for tumor patients. The relationship between it and immune homeostasis suggests that nutritional intervention may affect the efficacy of tumor immunotherapy. A variety of nutritional supplements such as ω - 3 polyunsaturated fatty acids vitamins dietary fiber probiotics arginine selenium and plant extracts all have immunomodulatory effects. They can act on tumor cells and immune cells affect the tumor microenvironment and when combined with immune checkpoint inhibitors can regulate the immune response and promote the recognition and killing of tumors by immune cells. In a variety of tumor animal model experiments and some preclinical studies it has been confirmed that they can significantly affect the effect of tumor immune checkpoint inhibitor therapy. This article will review the research progress in recent years on the immunomodulatory effects of various nutritional supplements and their relationship with tumor immune checkpoint inhibitor therapy so as to provide ideas for the in-depth study of anti-tumor treatment with nutritional supplements and the combined use of immunotherapy drugs and promote the development of individualized and precise nutritional immunotherapy.