Abstract： Coloanal anastomosis is a surgical procedure in which the colon is connected to the anus after rectal resection,and it can be divided into one-stage immediate anastomosis and two-stage(delayed)coloanal anastomosis.Based on relevant literature and team practices,the authors explore the indications,technical essentials,complications,and functional aspects of both immediate and delayed coloanal anastomosis.When performing coloanal anastomosis,it should make rational choices based on the patient's indications,condition,and actual technical situation of the surgeon.In sphincter-preserving surgery for low rectal cancer,the success of coloanal anastomosis depends on achieving effective reconstruction that ensures oncological safety,anatomical integrity,and func-tional recovery.