Objective To investigate the clinical efficacy of rituximab re-treatment in patients with relapsed idiopathic membranous nephropathy (IMN) and its impact on renal function and blood pressure. Methods A total of 90 patients with relapsed IMN admitted to Jiaozuo People’s Hospital from May 2025 to December 2025 were selected as observation subjects and were divided into the observation group (n＝45) and control group (n＝45) according to the random number table method. The control group received conventional glucocorticoid combined with immunosuppressive agent retreatment, while the observation group received rituximab retreatment. The clinical efficacy, renal function indicators (serum creatinine (Scr), blood urea nitrogen (BUN), 24-hour urinary protein quantification, estimated glomerular filtration rate (eGFR)) after treatment, blood pressure indicators (systolic blood pressure (SBP), diastolic blood pressure (DBP)), and adverse reactions were compared between the two groups. Results The total effective rate of treatment in the observation group was superior to that in the control group (P＜0.05). Compared with the control group, the observation group had lower levels of Scr, BUN, 24-hour urinary protein quantification, SBP and DBP after treatment (all P＜0.05), while eGFR levels were higher (P＜0.05). No statistically significant difference in adverse reactions was found between the two groups (χ2＝1.216, P＝0.270). Conclusion Rituximab retreatment in patients with relapsed IMN can effectively improve clinical outcomes, enhance renal function, and control blood pressure, with a favorable safety profile.