Abstract: Objective To reduce the missed diagnosis rate of postpartum hemorrhage,improve the diagnosis of postpartum hemorrhage,reduce the occurrence of obstetric adverse events and the actual rate of postpartum hemorrhage,and improve the quality of obstetrics by using PDCA cycle management.Methods Pregnant women who gave birth in our hospital from 2017 to 2019 and from 2014 to 2016 were selected as the research group and the control group,respectively. Four steps(plan,do,check,and action) of the PDCA cycle were used to manage the pregnant women who gave birth in our hospital from 2017 to 2019. The detail steps were as follows. first of all,the postpartum hemorrhage rate of pregnant women delivered in our hospital from 2014 to 2016 was analyzed retrospectively. The possible missed diagnosis rate of postpartum hemorrhage and the number of adverse events were analyzed.Secondly,we set goals and made cause analysis to find out the main causes of missed diagnosis rate of postpartum hemorrhage,high actual postpartum hemorrhage rate and the occurrence of serious adverse events. Third,formulate countermeasures for the main reasons were developed. Fourth,the implement measures in accordance with the countermeasures were provided.Results The diagnosis rate of postpartum hemorrhage in 2017-2019(3.35%) was higher than that in 2014-2016(1.52%),and the difference was statistically significant(χ²= 103.189,P<0.001). The missed diagnosis rate in 2017-2019(1. 33%) was lower than that of 2014-2016(8.54%),and the difference was statistically significant(χ²= 774.966,P<0.001). The total incidence of postpartum hemorrhage in the 2017-2019(4.68%) was lower than that in the 2014-2016(10.064%),and the difference was statistically significant(χ²= 300.642,P<0.001). The number of adverse events in 2017 was significantly lower than before. No adverse events occurred in 2018 and 2019.Conclusion The application of PDCA cycle management can significantly reduce the missed diagnosis rate of postpartum hemorrhage,improve the diagnosis rate of postpartum hemorrhage,and reduce the actual rate of postpartum hemorrhage.In addition,it can improve the quality of obstetrics by reducing the adverse events caused by postpartum hemorrhage.