Abstract Objective To study the effect of an early childhood education machine on sedation and analgesia in children after cardiothoracic surgery. Methods A prospective randomized controlled study was conducted in a provincial hospital in China. Fifty-two patients (aged from 1 to 5 years) underwent cardiothoracic surgery (including: ventricular septal defect, patent ductus arteriosus, atrial septal defect, pulmonary stenosis, pulmonary sequestration and congenital cystic adenomatoid lung malformation) were divided into the study group (n = 26) and the control group (n = 26). The patients in the study group underwent intervention with an early childhood education machine (uniform type) in addition to routine standard treatment and nursing, while the patients in the control group only received routine standard treatment and nursing. Richmond agitation sedation score (RASS) and face, legs, activity, cry, consolability (FLACC) score of all of the patients were evaluated, and the negative emotions (self-rating anxiety scale (SAS) score and self-rating depression scale (SDS) score) of the parents of the two groups were compared. Results There was no significant difference in the general clinical data between the two groups. The RASS and FLACC scores in the study group were significantly lower than those in the control group, and the SAS and SDS scores of the parents in the study group were significantly lower than those in the control group. Conclusion The application of an early childhood education machine for children after cardiothoracic surgery can effectively reduce postoperative agitation, improve sedation and analgesia of the patients, and ease the pessimistic mood of the patients’ parents.