Objective To explore the effectiveness of telemedicine-based exercise intervention in home cardiac rehabilitation for children with congenital heart disease. Methods A total of 96 school-age children with congenital heart disease were assigned to one of two groups chronologically. The control group (n=46) received routine home-based exercise training, while their counterparts in the experimental group (n=50) were subjected to telemedicine-based exercise intervention. A telemedicine exercise rehabilitation platform was constructed, individualized exercise protocol was formulated based on the child′s exercise capability, online exercise classes were provided to guide the exercise training, and real-time monitoring of the exercise was achieved. After 12 weeks of intervention, the 6-minute walk distance, exercise protocol adherence, quality of life, and satisfaction were compared between the two groups. Results After 12 weeks of the intervention, the above-mentioned parameters in the experimental group were significantly better compared to the control group (all P<0.05). Conclusion Telemedicine-based exercise, which combines telemedicine and exercise intervention, helps children with congenital heart disease improve exercise endurance and adherence, as well as enhances their quality of life.