The steps of catheter insertion for girls include sterilizing and inserting the catheter. 1. Sterilization: Before inserting the catheter, the doctor needs to sterilize his hands. Go to the patient’s bed, ensure the patient’s privacy, open the catheterization bag, put on disposable sterile gloves, lay a disposable sterile pavement towel, and disinfect the patient’s perineum. The first disinfection order is pubic mound, labia majora, labia minora, urethral opening, from the outside to the inside, from the top to the bottom. The second disinfection order is the same as the first time in reverse. 2. Intubation: lubricate the catheter with lubricating oil, separate the labia majora and labia minora with one hand, hold the catheter with forceps with the other hand and gently insert it into the urethra for 4-6 cm against the urethral orifice, and then insert it for another 1 cm when you see urine flowing out, release the hand that fixes the labia minora, fix the catheter, and collect the urine into the catheterization bag. Before intubation, tell the patient to breathe with the mouth open to facilitate muscle relaxation. Move gently when inserting the catheter to avoid damage to the urethra. Insertion of the catheter should be operated by a professional doctor to avoid adverse consequences.