1. Personal (especially female) hygiene of the perineum. The PH value in women’s vestibule and vagina is kept around 4.5, and bacteria are not easily reproduced; antibodies are produced on the mucous membrane surface of the lower urinary tract; the integrity of the mucous membrane has a mechanical blocking effect, so excessive washing is not desirable. Especially after menopause, due to the decline of estrogen, PH changes are prone to infection. 2, urination after sex or a single oral antibacterial drug after sex. It is effective for preventing recurrence. 3.The initial treatment should be thorough. After the initial infection treatment, the pathogenic bacteria latent down and re-infected under suitable conditions. 44% of patients recur at least once within 12 months. Those with frequent recurrence of infection use low-dose antibacterial drugs once a day, three times a week, for long-term application. If you are worried about the side effects of long-term application of low-dose antibiotics, you can also replace them with herbal medicine at the appropriate time, which is effective in preventing recurrence. 4. Estrogen replacement therapy (such as intravaginal use of estrogen ointment) in postmenopausal women can significantly reduce the recurrence rate. However, it should be confirmed by gynecologists and mammologists before use (to confirm if there are any contraindications). 5. Thoroughly control and remove the foci of infection in the body, such as chronic prostatitis, epididymitis, pelvic inflammatory disease and urethritis. 6, timely correction of primary lesions causing infection, such as urinary tract obstruction (stones, deformities, benign prostatic hyperplasia), foreign bodies (including urinary catheters) and reflux. 7.Actively treat diseases causing systemic immune deficiency such as diabetes, chronic wasting disease, uremia, chronic hepatitis and liver stiffness. 8.Prevention of urinary catheter infection. Correct and standardized use can reduce the infection rate: (1) closed drainage and regular replacement of sterile drainage bags can reduce the infection by half. (2) Whether bladder flushing is needed: flushing drugs stimulate or corrode the mucosa and destroy the mucin defense mechanism; the operation process destroys closed drainage and inevitably causes contamination; low concentration of drugs can induce bacterial resistance. (3) Those who leave the catheter in place should choose the appropriate catheter, too thick, too thin, too soft and too hard are not suitable. The choice of silicone balloon catheter, polyethylene balloon catheter and 16F is preferable. (4) Enhance care: ① Daily perineal irrigation (change bladder irrigation to perineal irrigation), i.e. washing the external urethral opening with sterile saline to remove urethral secretions and pus scabs. ② Strictly pay attention to aseptic operation, indwelling urinary catheter connected to sterile closed drainage, change the urine collection bag once a day, and re-sterilize and sterilize various joints when changing. Try to shorten the retention time. The partially dislodged urinary catheter should be replaced if it cannot be reinserted. ③ Long-term indwelling should pay attention to the penis turned up against the abdominal wall fixed to prevent compressive necrosis at the junction of the fixed section of the urethra and the overhanging section, forming a urinary fistula. ④The tube and urine bag should not be higher than the bladder level. 9, female friends after the stool, with hand towel wipe, from to back wipe, to avoid fecal contamination to the urethral orifice. After the stool, such as cleaning the anus should also do so. Can not use the way sitz bath to do. 10, reduce or avoid colds, cold, anger, staying up late, holding urine for a long time, overexertion. Drink more water appropriately (follow the advice of your doctor if you have heart failure or renal failure and restrict water intake).