Background: This study explored the clinical effect of implementing WeChat-based preoperative health education for parents of children with restrictive ventricular septal defect. Methods: A prospective randomized controlled study was conducted in a provincial hospital on the southeast coast of China. Participants were randomly divided into an intervention (WeChat) group (n = 35) and a control group (leaflet) group (n = 35). The study explored the parents’ knowledge of preoperative care, the follow-up rate, and complications of children with restrictive ventricular septal defect. Results: The score of preoperative care knowledge of the WeChat group (66.9 ± 3.5) was significantly higher than that of the leaflet group (47.3 ± 6.3) (P = .006). Compared with the score of care knowledge at the first visit, the score of the WeChat group at the preoperation was significantly higher (P < .05), whereas the increase in the score of the leaflet group was not significant. The rate of lost follow-up in the WeChat group (0%) was significantly lower than in the leaflet group (16.7%) (P = .02). The complications in the leaflet group were significantly higher than in the WeChat group. Conclusions: Using WeChat to provide preoperative health education to parents of children with restrictive ventricular septal defect can effectively enhance the parents’ knowledge of preoperative care and reduce the occurrence of complications and loss to follow-up.