Objective To explore the influence of cesarean scar pregnancy (CSP) correlative risk factors of intraoperative blood loss.Methods The clinical data of 410 patients with CSP who received surgical treatment in Nanchong Central Hospital and Wuhan maternal and child health care hospital from January 2013 to January 2019 were retrospectively analyzed. According to the amount of intraoperative blood loss, they were divided into bleeding group (67 cases) and control group (343 cases). The clinical characteristics of CSP patients in the bleeding group and the control group were compared. Multivariate binary logistic regression was used to analyze the possible factors that may affect the intraoperative bleeding in CSP patients, and the receiver operating characteristic (ROC) curve was drawn to evaluate the risk factors. Results Univariate analysis showed that there were significant differences in age, CSP focus clearance operation mode, menopause days, gestational sac maximum diameter and CSP classification between bleeding group and control group (P＜0.05). Multivariate logistic regression analysis showed that the surgical method, the largest diameter of gestational sac and the classification of CSP were the independent risk factors of hemorrhage during CSP operation (P＜0.05). ROC analysis showed that the area under the curve of the largest diameter of gestational sac, classification of CSP and surgical method of CSP lesion removal were 077 (95% CI=07130827, P＜0001), 075 (95% CI=06860815, P＜0001) and 0438 (95% CI=02730423, P＜0001), respectively. The best cut-off value of the largest diameter of gestational sac was 3cm, the sensitivity was 852%, and the specificity was 691%.Conclusion The bleeding during CSP operation was affected by the operation mode of CSP focus clearance, the maximum diameter of gestational sac and the classification of CSP. Gestational sac diameter＞3cm and CSP type Ⅲ were the high risk factors of intraoperative hemorrhage.