The choice of treatment plan for gastric cancer depends on the stage of gastric cancer, i.e. how early or late gastric cancer is detected. Early gastric cancer refers to cancer confined to the mucosa or submucosa layer, and regardless of whether there is lymph node metastasis or not, gastroscopic resection is feasible, which is less invasive and has quick recovery after surgery, and some of them can achieve the effect of endoscopic cure without adjuvant radiotherapy or chemotherapy after surgery. Early gastric cancer usually does not cause discomfort, so gastroscopy is advocated for early diagnosis and treatment. The main purpose of radiotherapy for gastric cancer is preoperative or postoperative adjuvant and palliative treatment, which helps to improve the life. The specific applications are as follows: 1. postoperative radiotherapy is recommended for T3 to stage IV or lymph node positive gastric cancer; 2. preoperative radiotherapy is recommended for locally advanced or progressive gastric cancer that cannot be surgically resected; 3. palliative radiotherapy is recommended for gastric cancer with local regional recurrence of tumor or distant metastasis. The specific treatment methods for gastric cancer will be reasonably formulated by doctors according to the pathological type and clinical stage of the tumor, combined with the patient’s condition and organ function status, with the aim of achieving radical cure or maximum control of the tumor, prolonging the patient’s survival and improving the quality of life.