Objective:To evaluate the role of permanent sigmoid colostomy created through the extraperitoneal route combined with pelvic floor peritoneal reconstruction after laparoscopic Miles surgery for lower rectal cancer.Methods:A total of 88 patients undergoing laparoscopic Miles surgery at Gastrointestinal Center of Northern Jiangsu People's Hospital from Apr 2016 to Apr 2020 were divided into extraperitoneal ostomy group(40 cases) and transperitoneal ostomy group (48 cases).Results:There were no significant differences in operating time, stoma-forming time, intraoperative blood loss, first exhausting time, first defecation time and hospital stay between the two groups (all P>0.05). There were 17 cases of complications in observation group vs. 16 cases in control group ( χ2=0.782， P=0.376). After 12 months, the complications in observation group were significantly less than control group ( χ2=8.601， P=0.003). There was no parastoma hernia in observation group vs.7 in control group ( χ2=4.502， P=0.034). The satisfaction rate of ostomy control defecation in observation group (70%) was significantly higher than that in control group (38%) after 12 months ( P=0.001). Conclusion:A permanent sigmoid colostomy created through the extraperitoneal route combined with pelvic floor peritoneal reconstruction during laparoscopic Miles surgery is safe and feasible, with fewer complications and better defecation function than that of the stoma through transperitoneal approach.