The first hurdle: respiratory hurdle. Premature infants lack PS, immature lung development, poor respiratory function, prone to apnea and respiratory failure, etc., so the first level; second level: infection level. Premature infants have poor immunity and barrier function, insufficient auto-cellular immunity and antibody synthesis, weak resistance, prone to sepsis, NEC, infectious pneumonia, etc.; the third hurdle: feeding hurdle. Premature infants have weak sucking and swallowing ability, relaxed cardia sphincter, small gastric capacity, prone to choking, milk spillage, vomiting, aspiration pneumonia, etc.; the fourth hurdle: jaundice hurdle. Premature infants with incomplete liver function, immature liver, poor bilirubin binding and excretion capacity, etc. are prone to increased jaundice, resulting in jaundice or bilirubin encephalopathy and other risks; the fifth hurdle: anemia hurdle. The smaller the weight of preterm infants, the sooner the hemoglobin, red blood cells and platelets begin to decrease after birth, prone to anemia and bleeding; sixth: weight off. Due to poor digestive function, prone to diarrhea, bloating, etc., coupled with liver function, poor intestinal function and other factors prone to preterm infants slow weight growth, which in turn leads to malnutrition, poor health, easy to infections, etc.; seventh pass: circulation off. Premature infants have a 12% higher incidence of symptomatic PDA and poor compensatory capacity of heart function, which can lead to heart failure, hypotension, pulmonary and renal impairment, etc.; the eighth hurdle: body temperature hurdle. Premature infants have a large body surface area, less subcutaneous fat, less fat and carbohydrate reserves, which can easily cause the body temperature does not rise. Their sweat gland function is incomplete, poor development of the thermoregulatory center, prone to parcel fever, etc.