Walnuts are nutty food with nutritional value, but they do not cause cancer and are not harmful to cancer patients. Walnuts are nutritious food, high in protein and vitamin E. Every 100g of walnuts contains about 14.9g of protein and 43.21mg of vitamin E. In addition, they contain vitamin potassium, calcium, zinc and iron, which can help to supplement the human body’s nutrition. However, walnuts as food do not have any efficacy and function, and there is no relevant research showing that walnuts have carcinogenic hazards. Cancer is a malignant tumor, and its occurrence is a complex process that can be caused by a combination of chemical, physical, biological and genetic factors. Consumption of high salt, smoked, salted and moldy food in daily diet is also one of its risk factors. It is recommended to keep a good mindset, have a balanced diet, supplement the body with a variety of nutrients, and reduce the consumption of high-salt, smoked and pickled foods and not eat moldy foods in daily life.