Kidney puncture is performed under ultrasound positioning, with local anesthesia and few complications, which is a relatively easy and safe diagnostic method. Many patients have this question: “I have already checked my kidney function and urinary routine, why do I still need a kidney puncture?” To summarize, the purpose of kidney puncture is: to clarify the diagnosis, guide the treatment and judge the prognosis. Firstly, there can be many different pathological types of glomerular diseases, which must be clarified by renal puncture biopsy. Through renal puncture biopsy, the pathological type and degree of severity of renal lesions can be clarified, which helps to clarify the etiology of secondary glomerular diseases and the localization of certain renal diseases (such as acute interstitial nephritis or acute tubular necrosis). Secondly, the treatment of different pathological types of glomerular diseases and different etiologies of renal diseases varies. Therefore, reasonable treatment can be performed according to the renal pathology results to avoid various adverse complications brought by blind treatment. In addition, renal pathology results are also important for judging the prognosis.