Proton heavy ion is generally used to treat tumors in the central nervous system, head and neck tumors, abdominal and pelvic tumors and other tumors in the early and middle stages of limitation, and the effect will be better. Tumor of central nervous system: In treating this kind of tumor, proton heavy ion can focus on the tumor site for penetrating treatment, and it will not affect other normal tissues in the surrounding, and will not cause damage to the central nervous system and symptoms. Head and neck tumor: this kind of tumor is close to other organs, using proton heavy ion treatment can avoid damage to eyes, ears and other organs. Abdominal and pelvic tumors: for patients with tumors in the abdominal cavity, pelvic cavity and other large areas of influence, a powerful irradiation of the tumor foci by proton heavy ion can also be used to achieve the therapeutic purpose. Proton heavy ion therapy belongs to one kind of radiotherapy, which has the characteristics of high energy level and strong penetration, and has certain advantages over traditional radiation therapy. This kind of radiation therapy is a non-invasive technology without pain, and it will not harm the normal cells near the tumor cells, so the treatment will cause less harm to the patient.