The complications of anal preservation surgery for low rectal cancer are mainly the following: first, the most common complication is anterior rectal resection syndrome, this syndrome is due to the reduced compliance of the original newly built rectum after rectal resection, when the feces in the colon is discharged to the rectum, it will cause yellow defecation due to stimulation, so it will lead to frequent defecation and at the same time can cause a feeling of anal swelling; second, the most serious Second, the most serious complication is anastomotic fistula, the anastomosis does not grow well and the stool leaks into the abdominal cavity through this opening causing complications; third, bleeding after surgery, including abdominal bleeding and anastomotic bleeding; fourth, abdominal infection, incisional infection; fifth, sexual dysfunction, because during surgery, some nerve endings of the reproductive system need to be removed, and damage to the nerve endings will lead to sexual dysfunction after surgery, especially Sixth, urinary dysfunction, because the same vegetative nervous system will be more or less damaged during the operation, which will lead to urinary dysfunction; seventh, recurrence of tumor, for some patients in the middle and late stage, postoperative recurrence is also one of the complications. Besides, there are also some surgeries with complications, including other complications such as intestinal obstruction and intestinal adhesions.