The following precautions must be taken for indwelling catheterization: 1. The urethral opening and the urethral tube must be disinfected regularly, usually 1-2 times a day, usually with iodophor, because iodophor is less irritating to the mucous membrane of the urethra. 2. The tube must be clamped regularly, especially if there is bladder function or for exercising bladder function. If the patient’s bladder bulges up or if the patient has a very obvious urge to urinate, the tube must be released to urinate, and the tube must be clamped after urination. If the catheter is not clamped for a long time, it will easily lead to loss of bladder function or bladder atrophy, which will lead to serious consequences.3. If the patient is in critical condition, the 24-hour in and out volume must be recorded, and the amount of urine must be recorded each time the catheter is passed, and the total urine volume for 24 hours must be reported to the nurse or doctor.