Objective To explore the mechanism of Bushen Wenyang Huayu formula in regulating the Notch1 / Twist1 signaling pathway-mediated epithelial-mesenchymal transition ( EMT ) in the treatment of endometriosis. Methods SD female rats were randomly divided into Sham operation group, Model group, BWH-H group, BWH-L group, and Dienogest group. The EMs rat model of Kidney Yang Deficiency was constructed by autologous transplantation combined with ice water bath. After the modeling was completed, BWH-H group and BWH-L group were respectively given high and low-dose medicinal solutions of Bushen Wenyang Huayu formula by gavage. Dienoges group was given dienogest tablets by gavage, while Sham operation group and Model group were given an equal volume of distilled water by gavage for 21 consecutive days, weight, volume, and adhesion degree of ectopic lesions and uteri were observed. Serum levels of sex hormones were determined by enzyme-linked immunosorbent assay, E-Cadherin, N-Cadherin, Vimentin, Notch1, and Twist1 proteins were detected by immunohistochemistry and Western blot, and gene expression levels of E-Cadherin, N-Cadherin, Vimentin, Notch1,and Twist1 were detected by RT-qPCR. Results Serum levels of estradiol ( E2), progesterone ( P ), folliclestimulating hormone (FSH), and luteinizing hormone (LH) were significantly increased in Model group compared with Sham operation group (P<0. 05). N-Cadherin, Vimentin, Notch1, and Twist1 protein and mRNA levels in uterine tissue were also significantly increased (P<0. 01, P<0. 05), while E-Cadherin protein and mRNA levels were significantly decreased (P<0. 01). The volume and weigh of ectopic lesions was significantly reduced in BWH-H group and BWH-L group traditional Chinese medicine and Dienogest group, compared with Model group (P<0. 05,P<0. 01), while E2, P, FSH, and LH levels were significantly decreased ( P<0. 05), N-Cadherin, Vimentin,Notch1, and Twist1 protein and mRNA levels in the uterine and ectopic lesion tissues were significantly decreased(P<0. 01, P<0. 05 ), and E-Cadherin protein and mRNA levels were significantly increased ( P< 0.01 ). Conclusions Bushen Wenyang Huayu formula can significantly inhibit the progression of endometriosis, and its mechanism may be related to the down-regulation of the Notch1/ Twist1 signaling pathway, thereby regulating the EMT process.