Abstract Objective To explore the clinical value of transperineal ultrasound measurement of the anterior uterocervical angle (AUCA) in predicting the onset time of full-term delivery of primipara. Methods 226 primiparas were selected from January 2019 to December 2020 in Wuxi People’s Hospital affiliated to Nanjing Medical University who underwent perineal ultrasound measurement of AUCA at 39 weeks of gestation and followed up to the delivery results. Among them, delivery was initiated after 41 weeks of gestation or still Pregnant women who underwent manual intervention without initiating labor were included in the delayed labor initiation group, and primiparous women who naturally started labor before 41 weeks of gestation were in the control group. Compare the difference of AUCA between the two groups, draw receiver operating characteristic curve (receiver operating characteristic, ROC) to evaluate the diagnostic efficacy of AUCA in predicting delivery delay. Results Among 226 primiparous women, 76 cases were in the delayed delivery group and 150 cases were in the control group. The AUCA of the delayed labor onset group and the control group were (92.6±10.9)° and (110.2±12.7)°, respectively. The difference between the two groups was statistically significant (P<0.05); AUCA predicted the area under the ROC curve for the delayed onset of labor was 0.84, Taking 100.2° as the best cut-off value, its diagnostic sensitivity, specificity, positive predictive value, negative predictive value and accuracy rate were 78.9% (68/76), 86.7% (130/150), and 77.3% (68/ 88), 94.2% (130/138) and 87.6% (198/226). Conclusion The AUCA of primiparas with delayed onset of delivery is less than that of primiparas with delayed onset of delivery. AUCA may be used as an indicator of delayed onset of delivery.