The main pathological types of nephrotic syndrome are microglomerular lesions, focal segmental proliferative sclerosing glomerulonephritis, and membranous nephropathy. Refractory nephrotic syndrome mainly refers to hormone resistance, hormone dependence and frequent relapses. Hormone resistance refers to 12-16 weeks of treatment with sufficient glucocorticoids (1 mg/kg/d) without remission; hormone dependence refers to relapse during dose reduction after initial remission or relapse within 2 weeks of drug discontinuation; frequent relapse refers to 2 relapses within 6 months or 3 relapses within a year after initial remission. Severe nephrotic syndrome is defined as patients with plasma albumin less than 25g/L, decreased vascular volume, significantly decreased plasma osmolality, tendency to hypotension, serum IgG less than 600mg/dl, and tendency to infection and arteriovenous thrombosis. Treatment: 1. Induction of remission: It is recommended to start combination therapy to improve the remission rate, reduce the recurrence rate and reduce the serious side effects of hormones. Hormone + cyclophosphamide: adequate amount of hormone (1mg/kg/d) and total cyclophosphamide 200mg/kd is safe and can be given intravenously daily, intravenously every other day or orally in small doses. Hormone + cyclosporine: half dose of hormone (0.5mg/kg/d) and cyclosporine A 3-4mg/kg/d, observed for 4-6 months with a trough concentration of 80-120ng/ml. Snapdragon has fewer side effects than CTX and is a promising maintenance drug. Hormone combined with two different types of immunosuppressant or two different types of immunosuppressant combination can also be chosen. 2.Long-term maintenance: long-term proteinuria of more than 2g/24 hours lasting 2-3 years will inevitably lead to chronic renal failure and ESRD, so urine protein should be reduced. It is generally believed that the relapse rate after hormone + cyclophosphamide induced remission is lower than those treated with cyclosporine or primaquine and hormone. If cyclophosphamide is contraindicated, resistant, or toxicity-limited, the combination of small amounts of hormone + small amounts of cyclosporine, primaquine, and azathioprine is selected for maintenance therapy. There are also examples of cyclosporine + raglan polysaccharide maintenance therapy. 3, diuretic and decongestant: the static order of human albumin in nephrotic syndrome does not elevate plasma albumin and has a definite benefit for diuresis, do not use it daily, it can be used intermittently. Tachyphylaxis + dihydrocoumaric acid has different effects, and the combined use has good diuretic effect. Tachyketuria should be given intravenously and after an intravenous dose of albumin. Excessive diuresis is one of the causes of acute renal failure, so the rate of weight loss should not be too fast, 0.5-1kg per day is appropriate.