Objective. A case-control study was performed to explore the efficacy and adverse reactions of Mirena combined with hysteroscopy when treating AUB. Methods. 108 patients with perimenopausal AUB treated in our hospital from June 2019 to December 2021 were enrolled, and their clinical data were collected and analyzed retrospectively. According to the mode of treatment, the patients were assigned into control group (54 cases) and study group (54 cases). The therapeutic effects were compared. Visual analog score (VAS) was adopted to evaluate the degree of incision pain, Barthel index score was adopted to evaluate the ability of daily living, quality of life scale was adopted to investigate the quality of life before and after treatment, and the changes of sex hormone levels, endometrial thickness, and menstruation were detected before and after treatment. The incidence of adverse reactions was calculated. Results. In terms of the therapeutic effects, 46 cases were cured, 6 cases were effective, and 2 cases were ineffective in the study group, and the effective rate was 96.30%; in the control group, 32 cases were cured, 10 cases were effective, and 12 cases were ineffective, and the effective rate was 77.78%; the effective rate of the study group was higher than that of the control group (
P
<
0.05
). In terms of VAS score, the VAS score decreased after treatment, and the VAS score in the study group was significantly lower than that in the control group at 1 week, 2 weeks, 1 month, and 3 months after treatment. With regard to the Barthel index scores after treatment, the Barthel index scores increased, and the Barthel index scores of the study group at 1 week, 2 weeks, 1 month, and 3 months after treatment were higher compared to the control group (
P
<
0.05
). In terms of the Barthel index scores after treatment, the Barthel index scores increased, and the Barthel index scores of the study group at 1 week, 2 weeks, 1 month, and 3 months after treatment were higher compared to the control group (
P
<
0.05
). Compared with those before treatment, the levels of FSH, LH, and E2 in both groups decreased remarkably (all
P
<
0.05
). In terms of the changes of endometrium and menstruation, the endometrial thickness, menstrual time, and menstrual volume were significantly improved after treatment (
P
<
0.05
). After treatment, the endometrial thickness, menstrual time, and menstrual volume in the study group were better than those in the control group (
P
<
0.05
). With regard to the scores of qualities of life, the scores of qualities of life decreased after treatment. Compared between the two groups, the scores of physiological function, psychological function, social function, and health self-cognition in the study group were lower compared to the control group. Regarding the incidence of adverse reactions, in the study group, there were 1 case of breast pain, 2 cases of vaginal bleeding, and no dizziness and nausea, and the incidence of adverse reaction was 5.56%; In the control group, there were 1 case of dizziness, 2 cases of breast pain, 4 cases of nausea, and 3 cases of vaginal bleeding, and the incidence of adverse reactions in the study group was 18.52%. The incidence of adverse reactions in the study group was lower compared to the control group (
P
<
0.05
). Conclusion. Hysteroscopy combined with Mirena when treating perimenopausal AUB can remarkably enhance the related symptoms, regulate the level of sex hormones, and remarkably reduce the amount of menstrual bleeding. The curative effect is better than hysteroscopy combined with dydrogesterone tablets, which is worth popularizing in clinic.