Because of the insidious onset of rectal cancer and the lack of specific symptoms, most patients are at advanced stage when they are diagnosed, and the tumor is huge and invades the pelvic wall, so they lose the opportunity of surgery. Even if the resectable stage II~III rectal cancer has a recurrence rate of 15%~65% in the local area after radical surgery, even if the surgery is performed according to TME principles, the recurrence rate of stage III rectal cancer is still as high as 20~30%, and the opportunity for reoperation is generally lost, and these patients often have symptoms such as anal swelling, perianal and sacrococcygeal pain, mucus and blood stool, and difficulty in stool, and the quality of life is obviously reduced. The general survival period is 3.5-13 months, and the 5-year survival rate is only 4%. Simultaneous radiotherapy and chemotherapy can be given in a shorter period of time, which can rapidly relieve symptoms and play a good palliative treatment purpose, and is the preferred program for advanced tumors. The enzyme has a high concentration in tumor cells, and radiotherapy can increase the activity of TPase, thus enhancing the effect of 5-fu. Secondly, 5-fu is a cell cycle specific drug, which has a specific killing effect on S-phase cells, all cells entering S-phase are killed, so that more tumor cells stay in G1 phase, which is exactly the cell sensitive to radiation. Thus, it prevents DNA synthesis and plays a role in radiotherapy sensitization. It can also reduce the reappreciation of tumor cells due to the prolonged course of sequential radiotherapy. Radiotherapy can significantly improve the local symptoms of patients, and the pain relief rate after radiotherapy is reported to be between 70-90%. In our group, the rate of complete relief of anal swelling was 44%, with an efficiency of 100%, and the rate of complete relief of pain was 56%, with an efficiency of 88%. The improvement rate of dyspareunia was 92.3%: In general radiotherapy, the tumor dose cannot be increased and the tumor control rate is low because the dose to important tissues and organs such as small intestine, bladder and femoral head is limited, while 3DCRT can irradiate the tumor area with higher dose while reducing the dose to normal tissues, thus improving the local control rate of tumor. The adverse effects of simultaneous capecitabine oral chemotherapy are well tolerated. The treatment of locally advanced and post-operative recurrent rectal cancer with VFRT is a better treatment mode, which can obtain better local control rate, effectively improve clinical symptoms and shorten the total treatment time, and the treatment toxicity is mild and well tolerated by patients, which greatly improves the quality of life of locally advanced and post-operative recurrent rectal cancer and achieves the purpose of prolonging the survival period.