In recent years, neonatology has developed rapidly, and the survival rate of 31-week preterm infants is over 95%. 31-week preterm infants face a series of problems after birth: first, respiratory system, early susceptibility to respiratory distress syndrome, requiring tracheal intubation to apply pulmonary surface active substances, and in severe cases, ventilator-assisted breathing. Secondly, electrolyte disorders. Electrolyte disorders are common in preterm infants and need to be corrected in time to avoid causing cardiac arrhythmias. Third, feeding intolerance. Premature infants are prone to feeding intolerance after birth, with inadequate energy intake, requiring intravenous nutritional support. Fourth, brain injury. Brain injury in preterm infants is an important complication that requires prompt MRI and timely treatment. There are also complications associated with preterm infants in the distant future, such as bronchopulmonary dysplasia and retinopathy of prematurity. 31-week preterm infants have a high survival rate after regular treatment and are less likely to have complications.