Objective:To analyze the causes of low prenatal ultrasonography display of partial fetal facial deformities and the application value of multi-plane continuous ultrasonography scanning in the display of fetal facial deformities.Methods:9240 pregnant women who underwent prenatal ultrasound screening were divided into two groups:4445 in the routine ultrasound screening group,and observation was made on the fetal coronal section and bilateral orbital cross section.Among the 4795 cases in the multi-planes continuous ultrasonography groups. When the suspicious deformity was found, three-dimensional imaging was used to determine whether the fetal face was abnormal,and the detection rate of the fetal face abnormality was compared between the two groups.Results:Two groups of 9240 cases of postpartum or after induced labor confirmed 31 cases of fetal facial deformity,40 deformities. The facial deformity rate was 0.34% (31/9240). And the conventional ultrasound screening set of facial malformations 14 cases (0.31%, 14/4445),multi section continuous ultrasound screening set of facial malformations of 17 cases (0.35%, 17/4795).There was no significant difference in the incidence of fetal facial malformation between the two groups (P < 0.05).Prenatal ultrasonography showed facial deformities in 5 cases (35.7%, 5/14) in the conventional ultrasound screening group, and prenatal ultrasonography showed facial deformities in 14 cases (82.4%, 14/17) in the multi-section continuous ultrasound screening group. The difference in prenatal ultrasonography showed statistically significant difference between the two groups (P < 0.01). Conclusion:There are many types of facial deformities in the fetus,and the formation reasons are complex,which are affected by the fetal posture,the abdominal wall thickness of the pregnant woman,and the amount of amniotic fluid.Prenatal ultrasound is not easy to observe the deformities of the ear,palate and facial cleft,showing a low rate.The best time for facial deformity is 18-24 weeks.Multi-section continuous ultrasonography for the observation of fetal facial can be more systematic observation,which is helpful for the detection of fetal facial malformations.