Quinolones are synthetic antibiotics commonly used in clinical practice, which mainly achieve bactericidal effects by inhibiting bacterial DNA synthesis, and are mainly used in clinical practice to treat 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, which are described as follows: 1. The first and second generations: such as nalidixic acid and pyridoxic acid, which have been rarely used because of their narrow antibacterial spectrum, relatively small antibacterial effect and many adverse reactions; 2. The third generation: which is also known as fasicidal drugs, such as norfloxacin, which is also known as fluoxacin, ofloxacin, levofloxacin, ciprofloxacin, lomefloxacin, etc., which are effective against Most gram-negative bacilli and some gram-positive bacteria have a strong effect, and also have an effect on anaerobic bacteria, chlamydia and mycoplasma. Good oral absorption and mild adverse reactions, commonly used in the treatment of urinary tract infections and prostatitis; 3, the fourth generation: such as moxifloxacin, gatifloxacin, anti-Gram-positive bacteria and anti-anaerobic bacteria to further enhance the role; 4, the fifth generation: stronger antibacterial effect, broader antibacterial spectrum, such as ganofloxacin, nifoxacin. It should be noted that it is prohibited for pregnant women and patients under 18 years old, and avoid sunlight exposure as much as possible during taking the drug.