Simple renal cysts are the most common of the cystic diseases of the kidney. They are mostly unilateral, rarely unilateral, and rarely occur bilaterally at the same time, mostly in adults. The specific etiology is still not very clear, and studies suggest that it may develop from tubular diverticula. The incidence of simple renal cysts increases with age as the number of distal tubular and collecting duct diverticula increases. Clinical manifestations and diagnosis of simple renal cysts: Most simple renal cysts are asymptomatic. If the cyst is large and combined with stone infection, there may be ipsilateral lumbago, microscopic hematuria, and percussion pain on the affected side.Ultrasound shows that the cyst is round or oval, located in the renal parenchyma, often protruding to the renal surface, the larger the cyst, the more obvious the protruding, the wall of the cyst is thin and smooth, and the cyst is a non-echoic area, with good translucence.CT shows that the cyst is clearly bounded by adjacent renal parenchyma, with a homogeneous density, and the CT values range from -10 to +20 Hu, with no enhancement in enhancement.IVU has no enhancement. IVU shows that the renal pelvis and renal calyces are displaced, or there is a curved pressure trace, and the renal pelvis and renal calyces do not communicate with each other. Treatment of simple renal cysts: If the cyst is small (<5cm in diameter) and the renal parenchyma has no obvious signs of compression, infection, malignancy, hypertension, etc., usually no treatment is needed, and yearly rechecking of ultrasound is sufficient. Surgical treatment should be considered when there are the following conditions: 1, obvious low back pain; 2, recurrent urinary tract infections; 3, hypertension caused by cysts can not be excluded; 4, renal function changes due to cyst compression; 5, suspected malignant cysts. The main surgical treatments for simple renal cysts: 1, laparoscopic renal cyst decortication and decompression: the current preferred method, with precise efficacy, low trauma, low recurrence rate, and fast recovery; 2, open cyst decortication and decompression: a commonly used method in grassroots hospitals that don't have the ability to carry out laparoscopy, with reliable efficacy, low recurrence rate, high trauma, and slow recovery; 3, percutaneous renal cyst puncture and sclerotherapy: low trauma, high recurrence rate, Inconclusive efficacy.