Leflunomide can generally prevent relapse of nephrotic syndrome and can also be used to treat refractory nephrotic syndrome. Leflunomide is a small molecule isoxazole compound with immune and anti-value-added effects. Basic and clinical studies have shown that it can be used to treat a variety of autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus and psoriasis. In recent years, clinical studies have found that it can also treat immune-mediated renal diseases. Such as IgA nephropathy, membranous nephropathy and so on. Several randomized controlled trials and clinical observational studies in China have shown that leflunomide combined with glucocorticoids can effectively treat refractory nephrotic syndrome, reduce proteinuria, increase serum albumin levels, and stabilize renal function. Currently, Leflunomide is also often used in combination with other immunosuppressants to treat refractory nephrotic syndrome. At the same time, for patients with recurrent relapses, leflunomide can be used in combination to achieve the purpose of preventing relapse. During the treatment, it is still recommended to closely monitor the changes of urinary protein and urine routine to assess the condition in time. For patients with nephrotic syndrome, it is recommended to consult a regular hospital in time and standardize the examination and treatment under the guidance of a physician.