Background: Placenta previa is one dangerous disease which threatens the health of pregnant women and their fetuses. The purpose of this study was to evaluate the clinical value of ultrasound combined with magnetic resonance imaging (MRI) in screening for placenta previa complicated by placenta accreta.Methods: Seventy patients with abnormal fetal position admitted to our hospital from January 2019 to January 2020 were selected for the study. Patients were diagnosed by ultrasound alone, MRI alone, and ultrasound combined with MRI. Diagnostic accuracy, sensitivity, specificity and false positive and negative diagnosis rates were evaluated against the postoperative pathological examinations of the patients.Results: The diagnostic accuracy, sensitivity and false negative rate for ultrasound combined with MRI were 86.27%, 97.78% and 72.00%, respectively. These results were significantly superior to those of MRI or ultrasound alone (P<0.05). The specificity and false positive rate for ultrasound combined with MRI were 13.73% and 5.26%, respectively, which were not significantly different from those for MRI or ultrasound alone (P>0.05).Conclusions: Compared with ultrasound or MRI alone, ultrasound combined with MRI has higher accuracy and sensitivity in the diagnosis of placenta previa with placenta accreta, along with lower false positive diagnosis rates. These findings are clinically important for improving the diagnostic efficiency.