Introduction: Chronic heart failure (HF) is a major challenge for children with congenital heart disease (CHD). However, the global epidemiological burden and regional differences remain unclear. Objectives: This study aimed to analyze the global, regional, and national disease burden trends of CHD-related HF in children and adolescents from 1990 to 2021. Methods: The Global Burden of Disease 2021 dataset was analyzed to assess trends in children with CHD-related HF by sex, age group, socio-demographic index (SDI), region, and country . Decomposition analysis was employed to identify influencing factors. Bayesian Age-Period- Cohort and AutoRegressive Integrated Moving Average models were used to predict future trends. Results: Global age-standardized prevalence rates (ASPRs) rose from 104 to 114 per 100,000, reaching 2.90 million cases in 2021. Globally , the number of cases and ASPRs increased across SDI regions, age groups, and types of HF, and were driven primarily by population growth and epidemiological changes. High-SDI regions had the highest ASPRs, but they declined over time, while lower SDI regions experienced rapid increases in ASPRs and number of cases. The global prevalence is predicted to continue rising, with the ASPRs for males and females increasing by 4.2–4.5% and 5.1–5.4%, respectively , by 2036. Conclusions: The global burden of CHD-related HF in children has been increasing and although ASPRs were higher in high- SDI regions, the largest number of cases and most rapid increases were in low and low-middle SDI regions. Thus, targeted prevention and control strategies should be developed based on the specific conditions of each region.