Objective:To explore the method of sequential sector scan with 2D ultrasound through oral fissure (SSTOF) and its utilization in the cleft palate screening.Methods:Based on features of oral anatomy and ultrasonic beam, SSTOF was designed to screen cleft palate and the accuracy had been verified using specimens of aborted fetuses. This study recruited 7 154 women with singleton pregnancy who were screened for fetal malformations during 20-28 gestational weeks in the First Affiliated Hospital of Anhui Medical University from May 2020 to October 2020. In medical addition to routine screening, these subjects also underwent SSTOF to further verify its feasibility and imaging performance. Follow-up was performed by telephone and medical record review.Results:Clear images of the upper palate were acquired in five specimens of induced fetuses using SSTOF. Except for 56 cases lost to follow-up, a total of 7 098 fetuses were finally enrolled, of which 6 885 acquired satisfactory images using SSTOF, 213 did not due to inappropriate position, with a success image rate of 97%. SSTOF found cleft palate in 31cases, which were all confirmed after birth or induction, noting an accuracy rate of 100%.Conclusion:Sequential sector scan through oral fissure has a high clinical value on cleft palate screening in the second trimester with advantages of clear image, easy operation, and access to section views.