Objective To explore the predictive value of transvaginal three-dimensional ultrasound energy Doppler blood flow parameters for pregnancy outcomes of in vitro fertilization-embryo transfer (IVF-ET) in patients with infertility and adenomyosis. Methods A retrospective analysis was performed on 100 patients with infertility and adenomyosis (study group) and 40 patients with simple infertility (control group) who underwent IVF-ET in Handan First People"s Hospital between January and December 2022. All patients underwent examination of transvaginal three-dimensional ultrasound energy Doppler before IVF-ET, and blood flow parameters of transvaginal three-dimensional ultrasound energy Doppler were compared between the two groups. All patients were followed up from pregnancy to delivery to record pregnancy outcomes. The blood flow parameters of transvaginal three-dimensional ultrasound energy Doppler were compared between pregnancy group and non-pregnancy group. The independent risk factors affecting pregnancy outcomes in patients. The predictive efficiency of transvaginal three-dimensional ultrasound energy Doppler blood flow parameters for pregnancy outcomes of IVF-ET was evaluated by receiver operating characteristic (ROC) curves. Results There was no significant difference in mean thickness, volume, vascularization index (VI) and vascularization flow index (VFI) of endometrial-myometrial interface (EMI) between study group and control group (P>0.05). The flow index (FI) in study group was lower than that in control group, and proportion of morphological abnormality was higher than that in control group (P<0.05). In the 100 patients with infertility and adenomyosis, there were 60 cases with successful pregnancy and 40 cases with unsuccessful pregnancy after IVF-ET. EMI morphology, mean thickness, volume, VI, FI and VFI in pregnancy group were higher than those in non-pregnancy group (P<0.05). EMI volume and EMI-VFI were independent risk factors of IVF-ET pregnancy outcomes in patients with infertility and adenomyosis (P<0.05). The area under ROC curve (AUC) and cut-off values of EMI volume and EMI-VFI for predicting pregnancy outcomes of IVF-ET in patients with infertility and adenomyosis were (0.795, 0.672) and (3.085cm₃^{, 0.}597), showing good predictive efficiency. Conclusion Transvaginal three-dimensional ultrasound energy Doppler blood flow parameters have high predictive value for IVF-ET pregnancy outcomes in patients with infertility and adenomyosis.