Old Wang often left lumbar distension and discomfort in the past six months, thought it was lumbar spondylosis, paste a few ointment also did not improve, so to the hospital for examination, found that the cause of the original is a about 7 * 6cm “left kidney cyst”. In the doctor’s advice, the old Wang did “posterior laparoscopic left kidney cyst de-topping surgery”. During the surgery, the doctor made three small holes of 0.5-2cm in the left waist of Lao Wang, through which the minimally invasive laparoscopic surgery was completed. Within a few days, Lao Wang was discharged from the hospital with a smooth recovery. Renal cysts are mostly a common benign disease with a prevalence of 30%-50% as reported in the literature. Cysts compress the kidney and can cause damage to kidney function; there is also a risk of rupture and hemorrhage when hit by external forces; they can also be complicated by infection and even cancer. Therefore, large renal cysts (greater than 4 cm) or those with symptoms should be treated with surgery as early as possible. Posterior laparoscopic renal cyst decortication has the advantages of less injury, less bleeding, faster recovery and lower recurrence rate, and is the preferred way of renal cyst treatment.