The effects of cyclophosphamide on nephrotic syndrome are mainly to suppress the immune inflammatory response, reduce urinary protein, stabilize renal function, delay fibrosis and renal failure, and prevent progression to the uremic phase. Cyclophosphamide is mainly indicated for patients with hormone-dependent or hormone-ineffective nephrotic syndrome and is mainly synergistic with hormone therapy. Generally cyclophosphamide is not used as the drug of choice or alone for the treatment of nephrotic syndrome because it has certain toxic side effects, such as bone marrow suppression, liver damage, hair loss, chemical cystitis, and sperm deficiency, conditions that can cause serious complications. Therefore, before clinical use of cyclophosphamide, a more detailed assessment of the patient’s condition should be performed, and if necessary, a renal biopsy can be done to decide whether to use cyclophosphamide or to add other drugs based on the type of pathology on the renal biopsy.