Quinolones are synthetic antibiotics commonly used in clinical practice, which mainly achieve bactericidal effect by inhibiting bacterial DNA synthesis, and are mainly used in clinical practice for the treatment of urinary tract infections, respiratory tract infections, biliary tract infections, skin and soft tissue infections. According to the order of discovery and the range of antibacterial spectrum, there are now five generations, described as follows: 1. The first and second generations: for example, nalidixic acid and pyridoxine acid, which have been seldom used due to their narrower antibacterial spectrum, smaller antibacterial effect and more adverse reactions; 2. The third generation: that is, the sarsaparilla class of drugs, such as norfloxacin, which is also known as fluperacid, ofloxacin, levofloxacin, ciprofloxacin, and lomefloxacin, which is effective on the Most gram-negative bacilli and some gram-positive bacteria have a strong effect on anaerobic bacteria, chlamydia and mycoplasma. Oral absorption is good, adverse reactions are mild, commonly used in the treatment of urinary tract infections and prostatitis; 3, the fourth generation: for example, moxifloxacin, gatifloxacin, anti-Gram-positive bacteria and anti-anaerobic effect is further enhanced; 4, the fifth generation: antibacterial effect is stronger, the antibacterial spectrum is wider, such as ganofloxacin, nenofloxacin. It should be noted that pregnant women and patients under 18 years of age are prohibited, and try to avoid sunlight exposure during the medication.