Objective:To investigate the feasibility, method and effect of laparoscopic radical resection of colorectal cancer. METHODS: Two cases of colon cancer underwent laparoscopic radical right hemicolectomy, and one case of rectal cancer underwent laparoscopic Miles radical resection. Results: All three cases were successfully completed laparoscopic surgery. The intraoperative bleeding volume was 120 ml, 200 ml and 150 ml, respectively. The number of lymph node dissection was 16, 8 and 5, respectively. The postoperative recovery time of gastrointestinal function was 3 d, 5 d and 4 d. The time to fluid intake was 4 d, 6 d and 5 d. The time to bed activity was 4 d, 5 d and 5 d. The recent postoperative results were good, and there was no surgical complication. Conclusion: Laparoscopic radical surgery for colorectal cancer is safe and feasible, with the advantages of minimal trauma and fast postoperative recovery, and can achieve radical curative effects comparable to those of open surgery. Surgical method: Preoperative preparation is the same as conventional open surgery. After general anesthesia, the patient was placed in a modified lithotomy position, routinely disinfected and toweled, and a pneumoperitoneal needle was inserted through a 1 cm straight incision at the inferior umbilical rim, and a 10 mm Trocar was placed as a 30° laparoscopic observation hole after inflation, and CO2 pressure was maintained at 12 mm Hg. For right hemicolectomy, a 10 mm Trocar was placed in the left upper abdomen as the main operation hole, and 5 mm and 10 mm Trocars were placed in the left middle abdomen and right lower abdomen as auxiliary holes. The operator stood on the left side of the patient. In the Miles procedure for rectal cancer, a 10 mm Trocar was placed in the right lower abdomen as the main operation hole, and 5 mm and 10 mm Trocar were placed in the right mid-abdomen and left lower abdomen as the auxiliary holes. Radical right hemicolectomy: The right hemicolectomy was started from the ileocecal region with an ultrasonic knife, the right ureter and genital vessels were exposed and protected, the hepatic flexure was free to the middle of the transverse colon, and the right hemicolectomy was performed. The right hemicocele and its mesentery were removed, and the end of the ileum and the distal end of the transverse colon were blocked with silk ligatures. The right half of the colon and its mesentery, including the regional lymph nodes, were excised in one piece by dissecting the naked colonic vessels, severing and ligating the ileocolic artery, the right colonic artery, the right middle colonic vein and the right branch of the middle colonic artery respectively from the root. After suturing the mesenteric space, the adjuvant port was closed, the pneumoperitoneum was reconstructed, the abdominal cavity was irrigated with distilled water, and an abdominal drainage tube was placed in the Trocar hole of the right lower abdomen. A total mesorectal excision (TME) was performed for the combined abdominal perineal rectal cancer (Miles procedure). The right lower abdomen and pelvic dense adhesions were first separated by ultrasonic knife. The rectum and sigmoid colon were free from the right side, the bilateral ureters and genital vessels were exposed and protected, and the submesenteric arteries and veins were naked and cut off after double ligation with titanium clips, respectively, and the rectum was free to the level of the anal raphe. The left lower abdominal auxiliary hole was extended, the sigmoid colon was raised and cut, the distal end was wrapped with plastic gloves and put back into the abdominal cavity, the proximal end was marked with a silk ligature, the auxiliary port was closed and the proximal sigmoid colon was dragged out of the peritoneum for fistula. The perineal group entered the pelvic cavity through the posterior wall of the rectum, and the large part of the sigmoid colon, rectum and its mesentery were removed in one piece, and then removed through the perineal incision. The pelvic cavity was irrigated with distilled water and a pelvic drainage tube was placed from the perineum. All three cases in this group successfully completed laparoscopic radical surgery. In the first case, the operation time of colon cancer was 240 min, intraoperative bleeding was 120 ml, no cancer cells were found in the pathological examination of the upper and lower resected stumps, and 16 lymph nodes were cleared. In the second case of colon cancer, the operation time was 270 min, no cancer cells were found in the pathological examination of the cut edge, 8 lymph nodes were cleared, 200 ml of intraoperative bleeding, gastrointestinal function recovered on the 5th day after surgery and bed activity was started on the 6th day after surgery, and the patient was discharged on the 14th day after surgery. It took 90 min to separate the abdominal and pelvic adhesions of rectal cancer, and the whole operation time was 300 min. 150 ml of intraoperative bleeding, no cancer cells were found in the incision margin, 5 lymph nodes were removed, gastrointestinal function recovered on the 4th postoperative day, fluid diet and bed activity were started on the 5th postoperative day, and the patient was discharged on the 15th postoperative day. It has been confirmed in a large number of case studies that laparoscopic colorectal cancer surgery is comparable to open surgery in terms of postoperative survival rate, mortality rate and complication rate, and has the advantages of less trauma, less bleeding, less postoperative pain, faster recovery of gastrointestinal function and shorter hospitalization time. The intraoperative bleeding in the three cases of colorectal cancer was less than 200 ml, which was significantly lower than that of open surgery, and the reduction of bleeding was even more significant when compared with open surgery for rectal cancer Miles. In addition to the small incision in the abdominal wall and the mild systemic reaction to surgery, the heart rate of the three colorectal cancer patients was within 90 beats/min on the first and second postoperative days, while the heart rates of most of the conventional open surgery were around 100-110 beats/min on the first and second days. Moreover, the amount of intraoperative fluid infusion was significantly reduced, for example, the total amount of intraoperative fluid infusion in the first case of colon cancer was only 1500 ml. Laparoscopic tumor eradication, postoperative recovery of gastrointestinal function, fluid intake time, and time to get out of bed were basically similar to those of open surgery, but the hospitalization time was significantly shortened. With the increase of the number of cases, it is believed that the operation time will be further reduced. The reason why laparoscopic surgery can achieve radical results comparable to open surgery is that laparoscopic surgery follows the same principles of tumor surgery. The laparoscope has a magnifying effect, so the dissection of tissue structure is more careful and clear; the dissection and hemostasis with ultrasonic knife is lightly damaged to the tissue, and the thermal damage area is small, so the blood vessels can be naked, ensuring that the blood vessels are cut from the root ligation and the regional lymph nodes are thoroughly cleared; the laparoscopic grasping forceps only grasp a small amount of tissue to avoid contacting and squeezing the tumor. To perform laparoscopic colorectal cancer surgery well, one must have rich experience in open surgery. The selection of the indications for laparoscopic surgery depends to a large extent on the proficiency and experience of the surgeon in laparoscopic techniques. In the first case, the colon cancer had a history of prostate and appendiceal surgery and serious abdominal adhesions. The second colon cancer invaded the liver and duodenum, and the radical right hemicolectomy was successfully completed by a combination of laparoscopic and adjuvant incisional separation. The second case of rectal cancer invaded the liver and duodenum. In our experience, laparoscopic TME for rectal cancer has more advantages than open surgery: (1) the rectum is freed in the correct plane with ultrasonic knife operation, with minimal bleeding; (2) the magnified view of the laparoscope allows more precise identification and protection of the pelvic vegetative nerves. As with open surgery, laparoscopic surgery also allows for extraperitoneal sigmoid fistulae.