Objective To analyze MRI imaging findings and diagnostic value of total placenta praevia with placenta accreta. Methods 60 cases of patients with total placenta praevia with placenta accreta who were admitted to our hospital from January 2017 to October 2018 were selected, and all patients were given cesarean section and diagnosed by pathology. All patients were examined by ultrasound and MRI before operation. Imaging findings and diagnostic value were analyzed. Results Ultrasound imaging of total placenta praevia with placenta accreta showed that the blood flow was abnormally abundant from the placental eddy close to the myometrium, and there was no obvious blood flow signal in the middle, and the blood flow was extensively formed in the placental interspace, and there were thickened placenta, obviously increased blood pool, and disappeared space behind the placenta and the disappeared or significantly thinned hypoechoic band in myometrium. The MRI findings showed that the uterus was mostly melon-shaped, and T2WI showed there was local thinning or loss of uterine muscle wall, and the edge of uterine wall invaded by placenta was nodular or jagged, and uneven signal on the T2WI was shown in some patients with visible rich signal voids of vessel. Based on the results of surgical pathology, there was no significant difference in the detection rate of total placenta praevia with placenta accreta between by ultrasound and by MRI (80.00% vs 88.33%) (P>0.05). The detection rate of posterior inferior wall of MRI was significantly higher than that of ultrasound (P<0.05). Conclusion The detection rate of total placenta praevia with placenta accreta of MRI is similar to that of ultrasound, and the detection effect of posterior uterine placenta accreta is superior to that of ultrasound. MRI can be used as an important method for clinical diagnosis of total placenta praevia with placenta accreta.