The precautions for male patients’ catheterization are as follows: first, the necessity of catheterization should be assessed, and the doctor should explain the purpose of catheterization and precautions to the patient and family to reduce the psychological burden of the patient or family; second, disposable items for catheterization should be prepared, and suitable catheters should be selected; third, the process of catheterization must be strictly aseptic, and patients with long foreskin must flip the foreskin, thoroughly remove foreskin scale, strictly disinfect, lay The catheter should be evenly coated with sterile paraffin oil and fully lubricated, and when catheterizing, it should enter slowly along the natural curvature of the urethra to reach the bladder, drain urine, and be properly fixed; fourth, the catheterization must be marked and the care of the urethra should be explained to the patient and family members to avoid accidental pulling and causing urethral injury.