The pathogenesis of neonatal sepsis is more complex than. Modern medicine believes that it is mainly caused by E. coli, Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella and Group B Streptococcus infections. The ways of infection are: 1, intrauterine infection: when the mother has infection during pregnancy (such as sepsis, etc.), the bacteria can infect the fetus through the placenta bloodstream. The fetus may suffer from pneumonia, gastroenteritis, otitis media, etc. due to inhalation or swallowing of contaminated amniotic fluid, and then develop into sepsis. The bacteria can also enter the blood directly from the broken skin and mucous membrane due to poor disinfection, improper midwifery, resuscitation injury, etc. 3, postpartum infection: the most common, bacteria can be invaded from the skin, mucous membrane, respiratory tract, gastrointestinal tract, urinary tract and other ways into the blood circulation, the umbilicus is the most easily invaded portal of bacteria. Nosocomial infections are likely to occur in the following situations: 1. children treated in the neonatal care unit (NICU); 2. children with invasive treatments such as tracheal intubation and umbilical vein intubation; 3. children with long hospitalization days; 4. children receiving surgical treatment; 5. crowded wards; 6. long-term application of broad-spectrum antibiotic treatment.