For spinal cord injury patients, difficulty in urination is a daily problem. Some patients are unable to urinate at all and need intermittent catheterization many times a day, which seriously affects their quality of life. How to solve the problem of urination? We first need to understand the pathophysiological process of urination in patients with spinal cord injury, under normal circumstances, the spinal cord center of urination in the thoracic 12 to lumbar 1 segment, also known as the parasympathetic center, is the power of urination, that is, the dominant bladder contraction of urethral muscles, generating the pressure of urination, and urination out of the body. In patients with spinal cord injury this pressure to urinate is absent. In addition to the future to prevent the involuntary flow of urine, outside the urethra there are internal and external sphincter control, is to provide resistance to urination, to solve the problem of urination, we can not raise the pressure, but we have a way to reduce resistance, that is to make the sphincter resistance, that is, Botox will be injected into the sphincter muscle, the problem of urination will be solved.