The incidence and mortality rate of colorectal cancer has been increasing year by year in China, and has jumped to the second place of malignant tumors, especially in large and medium-sized cities such as Shanghai, Beijing and Guangzhou, which has become the first malignant tumor of the gastrointestinal tract, with 1.2 million new cases worldwide every year. As China’s population is gradually aging, the proportion of elderly colorectal cancer patients over 75 years old is gradually increasing. With age, the regenerative capacity of cells and tissues of the body decreases, the body’s function recovers slowly after surgery, the anastomosis and incision heal slowly, and complications such as anastomotic fistula, incision infection, and incision dehiscence are easy to occur after surgery. In more serious cases, many patients visit the emergency room due to acute abdominal obstruction, and malnutrition, anemia and intestinal obstruction will undoubtedly increase the risk of surgery and complications; elderly colorectal cancer patients often have systemic chronic diseases, such as cardiovascular diseases, chronic lung diseases, diabetes, renal insufficiency, etc., and have lower tolerance for surgery and anesthesia. Stress may induce acute attacks of chronic diseases and occult diseases, such as acute heart attack, cerebral thrombosis, pulmonary embolism and other unexpected events, resulting in serious adverse consequences. Pre-operative examination and multidisciplinary consultation are the prerequisites for surgery. Routine preoperative laboratory tests and abdominal CT, colonoscopy or ultrasound endoscopy can help assess the preoperative stage of colorectal cancer and the possibility of tumor resection. For patients with combined coronary heart disease, hypertension and other heart diseases, preoperative cardiac function assessment should be conducted for patients with heart disease, and preoperative blood pressure should be controlled below 140/90 mmHg. For patients with combined diabetes mellitus, it is safer to control blood glucose with insulin before surgery, and generally blood glucose should be controlled below 8 mmol/L. Some patients may be combined with cerebral infarction or renal insufficiency, so we should coordinate the consultation of neurology, nephrology and other specialties as soon as possible to ensure the safety of the perioperative period. Precise intraoperative operation Fine surgical operation and smooth anesthesia are the keys to successful surgery for high-grade colorectal cancer. Since the first laparoscopic right hemicolectomy was performed by Jacobs surgeon in 1990, the safety and long-term efficacy of laparoscopic colorectal cancer surgery have been proven by many randomized clinical trials such as COST and CLASICC, and recommended by the Ministry of Health’s Colorectal Cancer Treatment Standard. In traditional open surgery, the abdominal incision is usually about 20 cm, which results in long exposure time of abdominal organs and great trauma, obvious postoperative wound pain, late bedtime, and complications such as pneumonia and deep vein thrombosis in old and frail people, and is also unfavorable to the recovery of gastrointestinal function. With the magnification of laparoscopy, the anatomical level is clearer, the treatment of blood vessels is more precise, and the clearance of lymph nodes is more thorough, and the reconstruction of the digestive tract can be completed with a small incision of 5 cm after the intestinal tube is free. Radical resection of intestinal cancer in elderly patients should achieve clear anatomy, meticulous anastomosis, less intraoperative bleeding and no postoperative complications, so as to achieve faster and better recovery. For elderly colorectal cancer patients, the impact of CO2 pneumoperitoneum on intraoperative cardiopulmonary function is an issue that needs to be paid attention to. On the one hand, the interference of CO2 pneumoperitoneum can be reduced by lowering the pressure of CO2 pneumoperitoneum (which can be maintained at 10-12 mm Hg) and shortening the operation time as much as possible under the premise of ensuring the standardized radical treatment of tumor. pay attention to adequate oxygen supply, adjust respiratory frequency and tidal volume at the right time, and strengthen intraoperative monitoring of cardiopulmonary function, especially pay attention to monitoring of blood CO2 concentration and CVP, which requires an experienced anesthesia and intensive care team that can guarantee smooth perioperative overload. Third, diligent postoperative Careful observation and professional nursing are the guarantee that senior colorectal cancer can recover smoothly. After surgery, patients’ vital signs, incision, gastrointestinal decompression and abdominal drainage tube should be closely observed to maintain daily energy supply and balance of inlet and outlet, and senior patients should monitor lung condition, assist patients to turn over, pat back, drain sputum, and strengthen lung care by routine nebulized inhalation. Because of the small surgical incision and mild postoperative pain, we usually encourage the patient to move to the ground on the first day after surgery, which is not only beneficial to the recovery of gastrointestinal function, but also can reduce the occurrence of complications such as deep vein thrombosis and pulmonary embolism in the lower limbs. Usually, 2 to 3 days after surgery, the intestinal function can be recovered faster, and then the gastric tube can be removed and a small amount of water can be drunk to reduce the discomfort of pharynx, dry mouth and poor sputum discharge caused by the gastric tube.