Abstract:Objective：By analyzing the occurrence of unplanned reoperation，the objective of the study was to discuss the key monitoring measures of unplanned reoperation，in order to ensure the safety of perioperative patients. Methods：Surgeries conducted from 2016 to 2017 year，142 patients with unplanned reoperation in hospital were retrospectively analyzed；the patient information，surgical information，the causes of unplanned reoperation and the interval between two operations were statistically analyzed. Results：There were significant differences in sex ratio，age，prognosis，hospitalization cost，length of hospital stay and operation grade between non-planned reoperation and general surgery（p < 0.001），general surgery and cardiothoracic surgery prevention of postoperative hemorrhage after operation 0.65 days，prevention of incision liquefaction/infection 15 days after orthopedic operation，and prevention of piping/anastomotic fistula 4 days after obstetrics and gynecology operation. This is the focus prevention and control of unplanned reoperation. Conclusion：In order to effectively reduce unplanned reoperation and reduce medical risk，it is necessary to strengthen the safety supervision of key patients，key-level operations and key periods.