Antibiotic medications have a strength distinction. The intensity of antimicrobial drug use plays a very important role in the standardized and rational application of antibiotics. The intensity of antibacterial drug use refers to the limited daily dose (DDD) of antibacterial drugs consumed per 100 person-days = consumption of antibacterial drugs × 100 ÷ number of days of patients admitted during the same period, and the number of days of patients admitted during the same period = number of patients discharged during the same period × average number of days of hospitalization during the same period. The intensity of antimicrobial use belongs to this indicator, which can reflect the dynamics of drug use and the structure of drug use in different years, and the larger the value of DDD, the higher the frequency of the use of the drug. The intensity of antimicrobial use can measure the breadth and intensity of exposure to antimicrobials in the hospitalized population and clarify the intensity of antimicrobial use. Antibiotic drugs have a before-and-after distinction, with different intensity of use for different symptoms. Antibiotics are divided into three lines, the first line that is less toxic side effects, inexpensive, such as penicillin; the second line that is less toxic side effects, but the price is higher, such as cephalosporin; the third line of toxic side effects, most of the price is higher, such as vancomycin, etc., the general principle of antibiotics is the first line after the second line, the third line, so that the patient is favorable. Pay attention to the rational use of antibiotics, follow the doctor’s instructions.