Clinical examination of the urinary system color ultrasound need to hold urine, mainly color ultrasound in different tissues will have different echo intensity, so as to carry out specific analysis of lesions. Color ultrasound examination, the bladder urine can become a good reference standard, at the same time the human body after holding urine bladder volume will become larger, so the specific lesions in the bladder will be gradually revealed in the color ultrasound examination. If the human body does not hold the urine in place, it will lead to the formation of the same homogeneous signal with the bladder tissue and the bladder mucosa and the surrounding tissue, which will not be able to make an effective judgment. Therefore, it is necessary to hold the urine in the bladder during the urological examination. At the same time, when patients undergo renal ureteral examination, urine in the bladder is also able to show abnormalities, such as bladder and ureteral reflux, the human body to hold urine can be swept through the color ultrasound. Therefore, the urinary system examination, urine holding is a very necessary process.