Urinary extravasation is usually caused by urethral injury, which is the most common of all urinary tract injuries. The male urethra is 17-20 cm and is divided into the anterior urethra and posterior urethra using the urogenital diaphragm as the boundary. The anterior urethra includes the head, penis and bulb of the penis, and the posterior urethra includes the membrane and the prostate. Due to its anatomical characteristics, the male urethra is prone to injury. The female urethra is short and straight, 2.5 to 5 cm long, and has less chance of injury. Prevention methods: 1. Patients with urinary extravasation should pay attention to protecting the genital area from being damaged by external factors in their daily lives. Diet is mostly light, avoid spicy and stimulating food. If the condition is serious, you need to seek medical treatment in a timely manner. 2, urethral injury, emergency treatment, should be considered to minimize the serious complications of urethral stricture. 3. In addition to good anatomical alignment of the urethra, removal of hematoma urinary extravasation, good drainage of the wound, early application of antibiotics, and use of less irritating silicone or latex catheters as stent tubes are elements that should not be overlooked. Once the wound is infected, urethral stricture will be inevitable. 4, posterior urethral injury emergency treatment, the method is still controversial, a simple cystostomy, the second phase of repair urethral method, this method will lead to 100% of the posterior urethral stricture, undesirable; through the perineum a phase of urethral repair, only suitable for lighter injury, the patient’s general condition is relatively good patients; suprapubic incision bladder line urethral division plus traction, the method is simple, the efficacy is reliable, even if it fails, because the proximal end was traction Even if it fails, because the proximal end is tractored and the stenosis is short, it is easier to operate again and has a better chance of success.