Objective To explore the effect of Buzhongyiqi decoction combined with special mirabilite bag on postoperative wound pain and local effusion in patients with inguinal hernia tension-free repair. Methods A total of 100 patients who underwent inguinal hernia tension-free repair in Dahua hospital, Xuhui District, from January 2023 to December 2025 were selected and divided into control group and research group according to the random number table method, with 50 cases in each group. The patients in the control group were treated with special mirabilite bag on the wound, and the patients in the research group were additionally administered Buzhongyiqi decoction on the basis of the control group treatment. The prescription consisted of Astragalus (30 g), Codonopsis (15 g), Fried licorice (10 g), Atractylodes (10 g), Angelica sinensis (10 g), Bupleurum (10 g), Cimicifuga (8 g), and Tangerine (6 g). The prescription was modified according to the patient’s pain severity. For patients with severe pain, Wulingzhi (10 g), Puhuang (10 g), Yanhusuo (10 g), and Motherwort (30 g) were added. The visual analogue scale (VAS) score for pain, traditional Chinese medicine (TCM) syndrome score, time to first flatus,incision healing time,hospitalization period,inflammatory indicators, local effusion,clinical efficacy and complication incidence rates were compared between the two groups after treatment. Results After treatment, the VAS scores for pain at 3, 5, and 7 days after surgery, various TCM syndrome scores, levels of inflammation indicators in the study group were significantly lower than those in the control group (P<0.05). The time to first flatus, incision healing time, and hospitalization period in the study group were shorter, the postoperative 7-day incision fluid accumulation depth was shallower, and the urine volume on the 3rd day after surgery was more, and the improvement effect of local effusion was better (P<0.05); the clinical total effective rate of the study group was 92.0%, significantly higher than that of the control group’s 64.0% (P<0.05); there was no significant difference in the complication incidence rates between the two groups (P>0.05). Conclusions Buzhongyiqi decoction combined with special mirabilite bag has significant effect on postoperative pain, effusion and other symptoms in patients with inguinal hernia tension-free repair, which can effectively prevent postoperative infection and promote postoperative recovery.