Supervised pelvic floor muscle training (PFMT) has been recommended as the first-line treatment for women with stress urinary incontinence (SUI), but more evidence on whether adjunctive methods would provide additional benefits is needed.To compare the efficacy of PFMT with or without a home-based pressure-mediated biofeedback (BF) device.This multicenter assessor-blinded randomized clinical trial was conducted in the obstetric clinics of 5 participating tertiary hospitals in China. Participants included eligible women with new-onset postpartum SUI who were enrolled from March 28, 2022, to October 13, 2023.All participants received 3 months of supervised PFMT and were randomized to either the intervention (PFMT with a home-based pressure-mediated BF device) or the control group (home-based PFMT).The primary outcome was the severity of urinary incontinence evaluated by the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form after 3 months of supervised PFMT. The secondary outcomes included the cure and improvement rates, PFM strength, quality of life, self-efficacy, and adherence.A total of 452 participants (median age, 34 [IQR, 31-36] years; median body mass index [calculated as the weight in kilograms divided by the height in square meters], 23.71 [IQR, 21.37-25.97]; median time since delivery, 50 [IQR, 43-61] days) were included in the analysis, with 223 in the intervention group and 229 in the control group. Compared with the control group, the intervention group achieved a significantly greater reduction in incontinence severity (median, 3.00 [IQR, 1.00-6.00] vs 2.00 [IQR, 0-4.00] points; z = -3.05; P = .002), significantly increased cure rate (45 of 223 [20.2%] vs 20 of 229 [8.7%]; z = 12.02; P = .001) and improvement (132 of 223 [59.2%] vs 102 of 229 [44.5%]; z = 9.71; P = .002), significantly greater pelvic floor muscle strength (median, 26.00 [IQR, 17.00-38.00] vs 21.00 [IQR, 13.50-33.50] cm H2O; z = -2.28; P = .02), and a significantly greater correlation between subjective and objective adherence (r = 0.825 vs r = 0.627).In this randomized clinical trial, the efficacy of pressure-mediated BF combined with PFMT was superior to that of PFMT alone. These findings support the use of pressure-mediated BF devices for improving treatment outcomes for patients with SUI.ClinicalTrials.gov Identifier: NCT05115864.