Abstract: Objective To investigate the effect of formula milk feeding with high energy on postoperative outcomes and nutritional status of children with congenital heart disease in the pediatric intensive care unit(PICU). Methods According to the simple randomization method, 105 children with congenital heart disease who underwent cardiac surgery were divided into two groups. The control group(n=52)was given normal milk feeding(with energy of 67 kcal per 100 mL milk), and the observation group(n=53)was given Alfaré milk feeding(with energy of 80 to 100 kcal per 100 mL milk). Mechanical ventilation time for the treatment, nutritional status and cardiac function of the two groups were observed and compared. Results The postoperative mechanical ventilation time in the observation group was shorter than that in the control group(P<0.05); the levels of postoperative albumin(PA), transferrin(TRF), and retinol binding protein(RBP)in the observation group were higher than those in the control group(P<0.05). Postoperative cardiac function of the observation group was significantly better than that of the control group(P<0.05). Conclusion Formula milk feeding with high energy can improve the nutritional status of children with congenital heart disease in PICU, shorten the treatment time of mechanical ventilation, and improve cardiac function.