Newborns and infants are very fragile lives, but more and more newborns now suffer from congenital heart disease, which is a huge test for their life safety. The complexity of the disease and weak autoimmunity make it necessary to pay more attention to this situation. Accompanying it is the continuous and in-depth application of microscopy and computed tomography imaging technology in medicine, which provides conditions for solving congenital heart disease in newborns and infants. Therefore, it is necessary to actively carry out nursing care of 256-slice computed tomography imaging of neonatal and infantile congenital heart disease. The purpose of this article is to investigate the nursing research of 256-slice computed tomography imaging of neonatal and infantile congenital heart disease. Through computed tomography imaging technology and the use of CT equipment, the factors such as gender, age, premature birth, and low birth weight were compared. The effects of WAZ, HAZ, and WHZ were tested by chi-square test to explore the influencing factors of congenital heart disease and the best way to supply nutrition during nursing. The results show that the significant levels of age-specific weight (WAZ) are 0.05, 0.06, and 0.015, respectively. Only the low birth weight factor exceeds 0.05, which can be considered as one of the factors affecting congenital heart disease; age-specific height (HAZ) the significant levels were 0.064, 0.075, and 0.04, respectively, which exceeded 0.05 in terms of preterm birth and low birth weight, which could be considered as one of the factors affecting congenital heart disease. The results show that the application of computed tomography imaging technology plays an important role in the nursing and cure of congenital heart disease.