Ureteral intubation can be used for the diagnosis and treatment of urological diseases in the clinic, and it is widely used in the clinic. 1. Diagnostic purpose: It can be used for the determination of bladder capacity and residual urine; aseptic method to take urine specimen for bacteriological examination; monitoring of urine volume in critical patients; cystography and urethrogram; bladder water injection leakage test to check whether the bladder is ruptured; probing the urethra for stenosis and length of stenosis, and urethral length determination. 2. Therapeutic purpose: It can be used for chronic urinary retention caused by various reasons, such as urethral trauma, urethral stenosis, urethral stone, etc.; bladder drug perfusion; indwelling catheterization before surgery; intractable urinary incontinence; urethral trauma; preventing urethra from diverting urine after bladder and urethra surgery to promote wound healing; placing triple-lumen balloon catheter for compression of hemostasis and bladder irrigation after prostate surgery. 3. Contraindications: including acute urethritis, prostatitis, epididymitis and other lower urinary tract infections in the acute stage, severe urethral stenosis, after severe urethral injury. 4. Complications: may cause urethral injury, bleeding, bacteremia, sepsis, bladder spasm, bowel injury, bladder perforation and other complications. It is recommended that patients with the need for catheterization go to a regular hospital in a timely manner, and be operated by a healthcare professional.