There are no clinical studies that show a relationship between eating fish and fighting cancer. Fish is a food with hunger-relieving and nutrient-supplementing properties. Fish contains protein, folic acid, vitamins and other nutrients, which can replenish the energy needed by the human body, but it does not have anti-cancer effects. Cancer treatment methods mainly include surgery, radiotherapy, chemotherapy, etc. At the same time, cancer patients need to change bad habits, moderate exercise, diet emphasizes on nutritional comprehensiveness, and fish can be consumed to replenish the nutrients needed by the human body. When consuming fish, cancer patients should pay attention to the cooking method, pay attention to the diet of light, avoid deep-frying, braising and other cooking methods. Although fish does not have anti-cancer effects, cancer patients can choose fresh, light fish as a supplemental food.