As we all know diet is closely related to cancer. Healthy diet pattern can reduce the risk of some cancers while inappropriate diet structure may be an important inducement leading to systemic metabolic diseases such as tumors. In recent years more and more studies have explored the influence of different diet patterns on the morbidity mortality and treatment effect of tumors. This paper combs several diet patterns that have attracted much attention at present Including the relationship between Mediterranean diet Ketogenic diet and Pro-inflammatory diet and tumor and the possible mechanism of action. The results show that Mediterranean diet can reduce the incidence and overall mortality of colorectal cancer prostate cancer respiratory and digestive system cancer breast cancer oropharyngeal cancer oral cancer and throat cancer by regulating hormone levels activating antioxidant mechanism stimulating immune system and down-regulating carcinogenic factors. Ketogenic diet mode may slow down tumor growth by targeting glucose metabolism amino acid metabolism mitochondrial metabolism regulating gene expression regulating signal pathway and reducing vascularization level. It plays an important role in prolonging the survival time of patients and reversing the process of tumorinduced cachexia and has gradually become an effective anti-cancer treatment. The Pro-inflammatory diet contains more inflammatory components which may promote the occurrence and development of tumors by increasing the inflammatory level changing the state of microflora and affecting epigenetic remodeling.