Chronic pyelonephritis is mainly characterized by structural disorder of renal pelvis and renal calyces on ultrasound, and in severe cases, it is mainly characterized by renal atrophy and thinning of renal cortex. Chronic pyelonephritis is mainly caused by acute pyelonephritis. Repeated pyelonephritis can lead to thickening of the mucous membrane of the renal pelvis and calyxes, which will lead to structural disorder, and at this time, ultrasound mainly shows that the structure of the renal pelvis and calyxes is not clear. If the disease continues to progress, the glomeruli can be damaged, resulting in glomerular atrophy, and in severe cases, renal function will decline, which is mainly manifested in the ultrasound as thinning of the renal cortex and bilateral renal atrophy. Although chronic pyelonephritis has certain manifestations on ultrasound, it can not be diagnosed on the basis of ultrasound, but needs to be combined with the patient’s clinical symptoms, relevant laboratory tests, and if necessary, other imaging tests, to confirm the diagnosis. Patients with chronic pyelonephritis are advised to consult regular hospitals for standardized examination and treatment under the guidance of physicians.