Objective to explore the application of ultrasonic combined MRI in the diagnosis of fetal cardiac malformation. Methods the first phase selection in March 2015 to March 2016 in our hospital and the shenzhen city people''s hospital and routine prenatal ultrasound diagnosis of fetal cardiac malformations of 39 cases of pregnant women by MRI scan, and sonographic views photo with templates to create one of a corresponding MRI standard fault graph; The second phase selection in March 2016 to March 2016 in our hospital and the shenzhen city people''s hospital for routine prenatal ultrasound examination of fetal cardiac malformations of 57 cases of pregnant women as the research object, on the prenatal ultrasound screening, again with MRI standard fault graph based on MRI of 57 cases of pregnant women.Final will be a single ultrasonic diagnosis, ultrasonic joint MRI diagnosis and follow-up results autopsy results or after birth detailed comparison and analysis, compare the accuracy of two methods of diagnosis. Results through the investigation and follow-up results of an autopsy that ultrasonic joint MRI diagnostic coincidence rate was 98.24% (misdiagnosis 1 case, no leak diagnosis), significantly higher than that of single ultrasound diagnosis coincidence rate was 85.96% (5 cases of misdiagnosis and missed diagnosis of 3 cases), statistically significant differences in two groups of data (chi-square = 4.34, P < 0.05). Conclusion ultrasonic combined MRI can improve the detection rate and accuracy of fetal heart abnormalities.