Renal aneurysm is a rare renal vascular disease that is a permanent abnormal dilatation of the arterial wall following localized weakness or structural damage. Its incidence in the normal population is 0.01-1%, accounting for about 22% of visceral hemangiomas. Its etiology is mainly congenital dysplasia of elastic fibers in the middle layer of the renal artery, followed by acquired diseases such as renal arteriosclerosis, myofibrillar disease, nodular arteriolar ependymitis, syphilis, bacterial arteritis, and renal puncture injuries, etc. It is classified into three types according to the structure of the tumor wall. According to the structure of the aneurysm wall, there are three types of aneurysms: true aneurysms, pseudoaneurysms, and entrapment aneurysms. According to the location, they can be divided into extra-renal aneurysms and intra-renal aneurysms. The former mainly occurs in the main stem and the first branch of the renal artery, while the latter mostly occurs in small arteries of grade 2-3 or above in the renal parenchyma.Poutasse classified renal aneurysms according to their shape and location as systolic aneurysms, saccular aneurysms, entrapment aneurysms and intrarenal aneurysms, and all types of aneurysms can be mixed. Symptoms and signs of the disease and complications are related to the location, size and type of aneurysm, which may be manifested as low back pain, hematuria, abdominal pulsatile mass, hypertension, vascular murmur, etc. The symptoms of the disease are as follows