While antimicrobial drugs have cured and saved many patients’ lives, there are also adverse consequences caused by the irrational application of antimicrobial drugs, such as the increase of adverse reactions, the growth of bacterial resistance and the failure of treatment, which have a significant impact on patients’ health and even lives. The irrational application of antimicrobial drugs is manifested in many aspects: preventive drugs without indications, therapeutic drugs without indications, wrong selection of antimicrobial drug species and dosage, unreasonable route of administration, number of times of administration and course of treatment. In order to improve the level of antimicrobial treatment of bacterial infections, ensure the safety of patients’ medication and reduce bacterial resistance, it is necessary to use antimicrobials rationally. 1, the diagnosis of bacterial infection, the party has indications to apply antibacterial drugs. According to the patient’s symptoms, signs and blood, urine routine and other laboratory test results, the preliminary diagnosis of bacterial infection and the pathogenic examination confirmed the diagnosis of bacterial infection, the application of antimicrobial drugs are indicated. In the absence of evidence of infection by bacteria and the above pathogenic microorganisms, the diagnosis cannot be established, as well as viral infections, there are no indications for the application of antibacterial drugs. 2, as soon as possible to identify the cause of infection, according to the type of pathogen and the results of bacterial drug sensitivity test selection of antibacterial drugs. In principle, the selection of antimicrobial drugs should be based on the type of pathogenic bacteria and their sensitivity or resistance to antimicrobial drugs, that is, the results of bacterial drug sensitivity tests (hereinafter referred to as drug sensitivity). Therefore, in medical institutions with the conditions, inpatients must take the corresponding specimens before starting antibacterial therapy and immediately send bacterial culture to clarify the pathogenic bacteria and drug sensitivity results as soon as possible; outpatients can carry out drug sensitivity work according to the needs of their conditions. For critically ill patients, before the pathogenic bacteria and drug sensitivity results are known, the most likely pathogenic bacteria can be inferred from the patient’s onset, site of onset, primary lesion, underlying disease, etc., and given empirical antibacterial drug treatment first in combination with the local bacterial resistance status. 3, according to the characteristics of the antibacterial action of drugs and their in vivo process characteristics to select the drug. The pharmacodynamic (antibacterial spectrum and antibacterial activity) and human pharmacokinetic (absorption, distribution, metabolism and excretion process) characteristics of various antibacterial drugs are different, so each has different clinical indications. Clinicians should select antimicrobial drugs according to the above-mentioned characteristics of various antimicrobial drugs and according to the clinical indications. 4, antibacterial drug treatment plan should be integrated with the patient’s condition, pathogenic bacteria and antibacterial drug characteristics to develop. According to the pathogenic bacteria, the site of infection, the severity of infection and the patient’s physiological and pathological condition, the antimicrobial drug treatment plan should be formulated, including the choice of antimicrobial drugs, dose, number of doses, route of administration, course of treatment and combination drugs.