Pneumonia refers to inflammation of the terminal airways, alveoli and lung interstitium, which can be caused by pathogenic microorganisms, physical and chemical factors, immune damage, allergies and drugs. Bacterial pneumonia is the most common pneumonia and one of the most common infectious diseases. The pneumonia we talk about in daily life mainly refers to pneumonia caused by bacterial infection, which is also the most common type of pneumonia. Before the use of antibiotics, bacterial pneumonia posed a great threat to the health of children and the elderly. The emergence and development of antibiotics once significantly reduced the mortality rate of pneumonia. However, in recent years, despite the use of powerful antibiotics and effective vaccines, the overall mortality rate of pneumonia has no longer decreased, and has even increased.