The accurate collection of unplanned reoperation data can promote the standardized management of un-planned reoperation.By establishing a unified medical quality and safety supervision platform,Shanghai Hospital Devel-opment Center determined the rule base of unplanned reoperation and the classification of reasons for unplanned reopera-tion,collected relevant data of 37 municipal hospitals using the platform,combined with big data analysis and manual screening,and ensured the accuracy of the data.It also needed to be connected with electronic medical records and other systems to realize automatic determination and mining of data,so as to achieve the goal of warning high-risk surgery and optimizing surgical process.