Objective To summarize the serious complications of CT-guided microwave ablation of Ⅸ tumors in the liver and related prevention and treatment strategies. Methods A retrospective statistical analysis was conducted on 104 severe complications in patients with hepatic Segment Ⅸ tumors who underwent CT-guided percutaneous microwave ablation in the Department of Hepatobiliary and Pancreatic Surgery of our hospital from October 2013 to July 2023. Results The surgical success rate of the whole group was 100%. Postoperative complications were massive pleural effusion and liquid pneumothorax in 1 case， abdominal hemorrhage in 1 case， liver abscess in 1 case， ablation needle rupture in 1 case， delayed biliary tract injury in 1 case， and tumor-duodenal fistula in 1 case. The incidence of serious complications was 6.7%， and no deathoccurred during periablation. Conclusion CT-guided percutaneous microwave ablation for tumors in hepatic segment Ⅸ was associated with a low incidence of serious complications， indicating that the procedure was both safe and feasible.