Prenatal imaging diagnosis includes prenatal fetal ultrasound and fetal MRI, which is an important means of secondary prevention and control of birth defects. The advantage of fetal MRI is safe, and so far, it has not been found that MRI examination of 3.0 T or below will bring any adverse consequences to pregnant women and fetuses. MRI has become an important supplementary means for prenatal ultrasound diagnosis of fetal structural abnormalities in the second and third trimester of pregnancy, because of good soft tissue contrast, wide field of vision, multi-orientation and multi-parameter imaging, and advantages of non-radiation and non-invasion, and not affected by factors such as maternal obesity, oligohydramnios, and fetal head calcification. The purpose of fetal MRI examination is to confirm results of prenatal ultrasound examination, or when an abnormality is suspected by prenatal ultrasound without a definitive diagnosis. MRI examination may obtain more information from fetus than prenatal ultrasound, and make up for some deficiencies of prenatal ultrasound. Indications of fetal MRI include central nervous system congenital malformations suspected of fetus by prenatal ultrasound examination, ventricular dilatation, brain midline structural abnormalities, posterior cranial fossa widening or abnormalities of cerebellar vermis of fetus, whether fetal cleft lip accompanied by cleft palate or alveolar bone abnormalities, whether fetal auricle malformations associated with atresia of the external auditory canal or dysplasia of the middle and inner ears, extracardiac macrovascular malformations suspected by ultrasound examination, location and characterization of abdominal and pelvic masses, evaluation of intestinal malformations, genitourinary tract malformations and singleton twins complications, evaluation of curative effect and prognosis before and after treatment of fetal diseases, and evaluation before termination of pregnancy for severe diseases of fetus, etc.. Overall, fetal MRI examination can provide relevant information of fetus for prenatal diagnosis, eugenics and genetic counseling, and provide basis for fetal treatment plan formulation, delivery mode selection and doctor-patient communication. Although fetal MRI can make a standard and complete evaluation of fetal anatomy, it is still not the first choice for prenatal imaging diagnosis.