To summarize the nursing experience of life and developmental support of 3 preterm infants with birth weight less than 500 grams and gestational age less than 23 weeks, so as to provide a reference for clinical nursing.The main treatment programs of the 3 infants included tracheal intubation after umbilical cord disconnection, use of pulmonary surfactant replacement therapy, invasive and non-invasive respiratory support treatment, anti-infection treatment according to infants′ condition, treatment of patent ductus arteriosus, use of vasoactive drugs according to circulatory conditions, enteral and parenteral nutrition support, screening and treatment of retinopathy of premature infants, etc.Finally, the 3 infants hospitalized 112, 125 and 125 days, with deoxygenated completely and fed normally, and discharged after rehabilitation.It is suggested that, life support nursing and developmental support nursing for preterm infants can improve their survival rate and reduce the occurrence of complications and sequelae.