Objective To investigate the efficacy of laparoscopic natural orifice specimen extraction surgery (NOSES) in the treatment of colorectal cancer and its effect on inflammatory factors, immune function and anal function. Methods 94 patients with colorectal cancer were divided into control group (n=47) and observation group (n=47) randomly. The control group was treated with laparoscopic small incision surgery, and the observation group was treated with laparoscopic NOSES. The perioperative related indicators ［operation time, intraoperative blood loss, first time to get out of bed after operation, first time to exhaust after operation, first time to eat and number of lymph node dissection］, inflammatory factors ［serum tumor necrosis factor-α (TNF-α), C-reactive protein (CRP) and interleukin-6 (IL-6)］, immune function ［CD3+, CD4+, CD8+ and CD4+/CD8+］, anal function ［anal venous pressure, rectal maximum tolerance, anal maximum systolic blood pressure］ and complications were compared between the two groups.Results The observation group's operation time was longer comparing with the control group (P＜0.05), intraoperative blood loss was less (P＜0.05), and the first time of getting out of bed, exhaust time and eating time after operation were shorter (P＜0.05). There was no significant difference in the number of lymph node dissection between the two groups (P＞0.05). One day after operation, TNF-α, CRP and IL-6 in the two groups increased (P＜0.05), while comparing with the control group, the observation group were lower (P＜0.05). CD3+, CD4+ and CD4 +/CD8+ in the two groups decreased(P＜0.05), while comparing with the control group, the observation group were lower (P＜0.05). Three days after operation, the anal venous pressure, rectal maximum tolerance and anal maximum systolic pressure of the two groups decreased(P＜0.05), and comparing with the control group, the observation group was higher(P＜0.05). Compared with 25.54 % in the control group, the observation group’s total complications incidence was lower(P＜0.05). Conclusion Laparoscopic NOSES has a more minimally invasive advantage for patients with colorectal cancer, which can further shorten the postoperative recovery time, reduce the inflammatory response, and maintain the immune function and anal function of patients