Proton heavy ion is not suitable for all colon cancer patients and is not a conventional treatment for colon cancer. Colon cancer belongs to common malignant tumors, and the treatment is mainly based on surgery, chemotherapy and targeted therapy. And proton heavy ion belongs to one kind of radiation therapy, which is not commonly used in clinic for this kind of malignant tumors in cavity organs because it will lead to tumor rupture and perforation. If liver metastasis or lung metastasis occurs in colon cancer, this situation can be treated by proton heavy ion therapy to eliminate the local metastatic foci, which can control the progression of the disease as much as possible and improve the quality of life of the patients, but cannot achieve a cure. Therefore, proton heavy ion therapy is only for some colon cancer patients, and is not used as a conventional treatment.