Objective: To explore the ultrasonic image characteristics, vascularization blood flow characteristics and diagn[1]ostic value of Cesarean Scar Pregnancy (CSP). Methods: From July 2022 to July 2024, 100 pregnant women with a history of cesarean section diagnosed as CSP were selected as the CSP group, and 100 non-CSP pregnant women with a history of cesarean section at the same period were selected as the control group in a 1:1 ratio. Vaginal color Doppler ultrasonography was performed in both groups to compare the characteristics of ultrasound images and vascularized blood flow in scar sites, and receiver operating characteristic (ROC) curve was drawn to analyze the diagnostic value of ultrasound image characteristics and vascularized[2] blood flow in CSP. Results: In CSP group, the blood flow score between pregnancy sac and myometria was higher than that in control group, the Angle between pregnancy sac and myometria and the myometria thickness were lower than that in control group (all P < 0.05). The Vascularization Flow Index (FI), Vascularity Index (VI) and vascularization Flow Index (VFI) of the scar site in the CSP group were higher than those in the control group (all P < 0.05). ROC curve results showed that the AUC for diagnosing CSP were 0.788, 0.774, 0.733, 0.550, 0.744 and 0.773, respectively, for blood flow score between the gestational sac and myometrium, Angle between the gestational sac and myometrium, myometrium thickness in isthmus, FI, VI and VFI, indicating that the above indexes had certain diagnostic value for CSP. The AUC of the combined diagnosis of CSP was 0.961, and the combined diagnosis value was the highest. Conclusion: The ultrasonographic characteristics of the blood flow score between the pregnancy sac and the myometria, the Angle between the pregnancy sac and the myometria, the thickness of the myometria and the vascularization blood flow parameters of the scar site FI, VI and VFI have certain diagnostic value for CSP, and the combined diagnosis value of the six indicators is the highest.