To observe the effects of the intervention with fire needling therapy on the uterine microenvironment at the specific time points of menstrual cycle and evaluate the effects on the assisted reproduction. Sixty-eight patients of in vitro fertilization and embryo transplantation (IVF-ET) were randomized into an observation group (35 cases) and a control group (33 cases). The patients in the two groups all received post-IVF-ET corpus luteum support of the microstimulation scheme in the Clinical Reproduction Center of Jiangsu People's Hospital. In the control group, the regular sequential therapy of acupuncture was used. In the observation group, on the basis of the treatment as the control group, the intervention of fire needling therapy was applied after ovulation (the 1st time point, on the 1st day after ovulation) and at the end of premenstrual stage (the 2nd time point, 3 days before the menstruation). At the 1st time point, Shenshu (BL 23), Mingmen (GV 4) and Yaoyangguan (GV 3) were selected and at the 2nd time point, Shenshu (BL 23) and Ciliao (BL 32) were selected. The acupoints were stimulated from up to down and from the left to the right. The changes in TCM syndrome during the preparation, the endometrial thickness and types on the day of transplantation, the biochemical pregnant rate after transplantation and clinical pregnant rate were observed and compared in the patients of the two groups. After treatment, TCM syndrome scores were all reduced in the two groups (both P<0.05). In the observation group, the biochemical pregnant rate and clinical pregnant rate were slightly higher than those in the control group, without significant difference in comparison (both P>0.05). In the observation group, the endo-metrial thickness on the day of transplantation was higher than that in the control group (P<0.05). After treatment, the differences in TCM syndrome score and endometrial type were not significant statistically between the two groups (all P>0.05). The intervention of fire needling therapy at the specific time points of menstrual cycle relieves menstrual symptoms and increases endometrial thickness so as to assist embryo implantation in the patients of infertility.