Abstract：Objective：To observe the clinical efficacy of modified Danggui Shaoyao San combined with external hot compress of Chinese medicine based on the "simultaneous treatment of blood and water" method in patients with dysmenorrhea due to endometriosis （EMT）. Methods：A total of 104 patients with dysmenorrhea due to EMT admitted to the Department of Gynecology of Traditional Chinese Medicine， Xiangcheng Hospital of Chinese Medicine from January 2022 to January 2025 were enrolled and randomly divided into a treatment group and a control group using a random number table method，with 52 cases in each group. The control group received Mifepristone Tablets，while the treatment group received modified Danggui Shaoyao San combined with external hot compress of Chinese medicine. After three menstrual cycles of treatment，clinical efficacy and traditional Chinese medicine syndrome scores were compared between the two groups. The severity of dysmenorrhea was assessed using the Cox Menstrual Symptom Scale （CMSS）， and pain intensity was evaluated using the Visual Analogue Scale （VAS）. Endometrial hemodynamics [pulsatility index （PI）， resistance index （RI）， peak systolic velocity （PSV）， end-diastolic velocity （EDV）]， serum sex hormone levels [estradiol （E2）， luteinizing hormone （LH）， follicle-stimulating hormone （FSH）]， and serum pain mediator levels [prostaglandin E2（ PGE2），prostaglandin F2α（ PGF2α），nerve growth factor（ NGF）] were also monitored. Results：Finally，49 cases in the treatment group and 50 cases in the control group completed the study. After three menstrual cycles of treatment， traditional Chinese medicine syndrome scores， CMSS scores， and VAS scores decreased in both groups compared to before treatment，with the treatment group showing lower scores than the control group， and the differences were statistically significant （P＜0.05）. The RI and PI values decreased in both groups compared to before treatment，while EDV and PSV values increased，with the treatment group showing lower RI and PI values and higher EDV and PSV values than the control group，and the differences were statistically significant （P＜ 0.05）. Serum levels of E2，FSH，and LH decreased in both groups compared to before treatment，with the treatment group showing lower levels than the control group，and the differences were statistically significant （P＜0.05）. Serum levels of PGE2， PGF2α， and NGF decreased in both groups compared to before treatment， with the treatment group showing lower levels than the control group， and the differences were statistically significant （P＜0.05）. The total clinical efficacy rate was 91.84% （45/49） in the treatment group and 76.00% （38/50） in the control group， with a statistically significant difference between the two groups （P＜0.05）. Conclusion：The application of modified Danggui Shaoyao San combined with external hot compress of Chinese medicine based on the "simultaneous treatment of blood and water" method for dysmenorrhea due to EMT can effectively alleviate traditional Chinese medicine symptoms， reduce the severity of dysmenorrhea and pain intensity，improve endometrial hemodynamics，regulate sex hormone and pain mediator levels，and significantly enhance clinical efficacy.