Sodium chloride is an essential element for maintaining normal physiological functions in the human body. The main component of salt is sodium chloride. However when daily salt intake exceeds 6 grams defined as a high salt diet HSD it can lead to various adverse health effects. Numerous epidemiological studies have revealed a close association between HSD - induced inflammatory states and the occurrence and progression of various tumors. Nonetheless recent research has uncovered promising potential for salt in the field of anti-tumor therapy. Salt can accumulate in the interstitial and tumor microenvironments regulating the differentiation and activation of immune cells thereby enhancing anti - tumor immune responses. Additionally the hypertonic environment induced by high sodium levels can directly exert cytotoxic effects on tumor cells. As a safe and cost-effective potential therapeutic approach the challenge lies in avoiding adverse health effects caused by excessive dietary salt while leveraging its immunomodulatory and hyperosmotic properties for anti-tumor treatment. This review aims to elucidate the dual mechanisms by which high salt exerts its effects during tumor development and progression. By comprehensively analyzing these mechanisms we intend to provide a theoretical foundation and novel insights for the clinical application of high salt in cancer therapy paving the way for future anti-tumor strategies.