The process of breast radiotherapy is to determine the radiological indications, simulate the localization, outline the target area, plan design and plan evaluation, plan validation, and treatment implementation. 1. Determination of radiation indications: mainly including lesions within 5 cm. 2. Simulation of positioning: The main purpose is to simulate the situation during treatment, including helping the patient to take the appropriate position and fixation, and at the same time determining the location of the radiotherapy site, which is mainly determined by CT scanning. 3. Target area sketching: After the simulation positioning is completed, the acquired images are imported into the teaching system, and then the doctor will sketch the target area, which is the area to be irradiated. The target area is the area to be irradiated. At the same time, it is also necessary to outline the organs at risk and the areas that need to be protected, and to determine the dose of radiotherapy. 4. Plan design and plan evaluation: After the target area is outlined and the radiotherapy dose is determined, the dosimetrist will design the radiotherapy plan. After the design is completed, the doctor will review the plan and evaluate whether the plan meets the treatment requirements through DVH, CTV and other dose curves. 5. Plan validation: After the completion of plan design and plan evaluation, the dosimetrist will carry out plan validation, mainly to look at the difference between the actual beam dose and the calculated dose in the plan, and analyze the specific reasons if the difference is large. 6. Treatment implementation: after the plan verification is passed, the patient will enter the treatment implementation session, the therapist will carry out the patient’s position, verify whether the patient’s position is qualified through the CT scan, and operate the radiation therapy equipment to deliver the beam for treatment. It is recommended that the patient be followed up regularly under the guidance of the doctor after the treatment is completed.