To evaluate female anal sphincter by transperineal and transvaginal three-dimensional ultrasound, and to explore the application value of different exoanal ultrasound imaging methods in evaluating female anal sphincter. Methods Three-dimensional volume imaging of anal sphincter was performed by transperineal ultrasound (transperineal group) and transvaginal ultrasound (transvaginal group). The thickness of internal anal sphincter (IAS) and external anal sphincter (EAS) at 3 o''clock, 6 o''clock, 9 o''clock and 12 o''clock were measured, and the anal sphincter injury was evaluated by adjusting sectional ultrasound mode. the results were recorded and statistically analyzed. Results The measured value of IAS thickness at 12 o''clock was thinner in the transvaginal group than in the transperineal group, and the difference was statistically significant (P<0.05). The EAS thickness measurement value was thinner in the transvaginal group than the transperineal group at 6 o''clock and 12 o''clock, and the difference was statistically significant (P<0.05). The two groups of EAS and IAS measured values had good correlations in all 4 directions and all had statistical significance (P<0.05). 6 cases (5.94%) of IAS injury were detected, 16 cases (15.84%) of EAS injury, and 13 cases (12.87%) of EAS combined with IAS injury in the transperineal group. The corresponding data in the transvaginal group were 8 cases (7.92%), 17 cases (16.83%), and 9 cases (8.91%). The two groups had good consistency in evaluating anal sphincter injury and had statistical significance (Kappa=0.736, P<0.05). Conclusions Transperineal and transvaginal three-dimensional ultrasound have good correlation and consistency in the evaluation of female anal sphincter, both of which are good exoanal ultrasound imaging methods for evaluating female anal sphincter.