Abstract： Objective： This study observed the efficacy of du meridian moxibustion with different durations in treating primary dysmenorrhea of cold coagulation and blood stasis type，and investigated the dose-effect relationship. Methods：A prospective randomized controlled trial design was adopted. A total of 60 primary dysmenorrhea patients of cold coagulation and blood stasis type admitted to Gongchenqiao Street Community Health Service Center of Gongshu District，Hangzhou from February 2023 to September 2024 were selected and randomly divided into a treatment group and a control group using a random number table method，with 30 cases in each group. The treatment group received du meridian moxibustion for 30 minutes ， while the control group received the same therapy for 60 minutes. Clinical efficacy was compared between the two groups after three menstrual cycles of treatment and at three menstrual cycles after treatment completion. Visual Analogue Scale （VAS） scores for dysmenorrhea pain，dysmenorrhea symptom scores， and serum estradiol （E2）/progesterone （P） ratio were compared before and after treatment. Results： After three menstrual cycles of treatment and at three menstrual cycles after treatment completion，the total clinical efficacy rates showed no statistically significant difference between the two groups （P＞0.05）. After one， two， and three menstrual cycles of treatment and at three menstrual cycles after treatment， VAS scores decreased in both groups compared with those before treatment （P＜0.05）， but no significant intergroup differences were found （P＞0.05）. Dysmenorrhea symptom scores decreased in both groups at all time points （P＜0.05）， with no significant intergroup differences （P＞0.05）. After three menstrual cycles of treatment，the E2/P ratio decreased in both groups （P＜0.05）， with no significant intergroup differences （P＞0.05）. Conclusion： Both 30-minute and 60-minute du meridian moxibustion can improve primary dysmenorrhea of cold coagulation and blood stasis type， but there is no significant difference in total clinical efficacy between the two intervention durations.