Objective To analyze the imaging features and diagnostic value of prenatal MRI diagnosis of dangerous placenta previa implantation. Methods 71 cases of patients with dangerous placenta previa admitted to our hospital were selected, and they were examined by MRI before delivery. The cesarean section and pathology were used as diagnostic criteria to analyze the MRI imaging findings and diagnostic value of dangerous placenta previa implantation. Results Among 71 cases of patients with dangerous placenta previa, there were 23 cases of pure dangerous placenta previa and 48 cases of dangerous placenta previa implantation (13 cases of placental adhesions, 30 cases of placenta accreta and 5 cases of placenta penetration), and the latter MRI images showed 35 cases with uneven signal within the placenta, 20 cases with uterine protrusion, 33 cases with unclear junction between placenta and myometrium, 25 cases with low signal on T2WI, 25 cases with increased and thickening placental vascular shadow and 13 cases with bladder protrusion. The sensitivity, specificity and accuracy of MRI were 85.41%, 82.61% and 84.51% in detecting dangerous placenta previa implantation. The diagnostic sensitivity and specificity of MRI were 53.85% and 93.10% for adhesion type, and were 86.67% and 92.68% for the implantable type, and were 80.00% and 98.48% for penetrating type. Conclusion MRI has a high detection rate for dangerous placenta previa implantation, and the diagnostic sensitivity and specificity of implantable type and penetrating type are higher than those of adhesion type. And it can be used as an important method for the clinical diagnosis of dangerous placenta accreta implantation and its types.