Radiation therapy is divided into traditional external irradiation and intertissue irradiation. Traditional external irradiation is radiotherapy, which is often limited in its efficacy because of the large radiation field and the low tolerance of normal tissues. Radioactive particle implantation belongs to minimally invasive interventional radiotherapy, which is a new means of treating malignant tumors in the past 20 years. It is a new treatment method for malignant tumors developed in the past 20 years. The main purpose is to design the treatment plan by applying the radioactive particle treatment plan, that is, the TPS planning system, and then implant the radioactive particles into the tumor body according to the tumor’s size and morphology under the guidance of CT, ultrasound, or magnetic resonance or enter into the tissues invaded by the tumor. The radioactive particles emit continuous, short-range radiation to maximize the killing of the tumor tissue. Normal tissues are basically not damaged or only slightly damaged to achieve the therapeutic purpose, so the pain is relatively low. As a complementary treatment to traditional external radiation radiotherapy and chemotherapy, radioactive particle therapy for malignant tumors is characterized by good efficacy, few side effects and high safety.