Background: This study explores and analyzes the clinical characteristics and prognostic factors of hepatoblastoma (HB) in children under 6 years old and establishes a new risk-stratification system for individualized therapy. Methods: The clinical data of 382 pediatric patients under 6 years old (231 males and 151 females) who had been diagnosed with HB by pathology between May 2005 and May 2019 were collected. By analyzing the risk factors influencing the survival rate of patients with HB, a new risk-stratification system was established, and it was compared with previous risk-stratification systems by a receiver operating characteristic (ROC) curve. Results: (1) According to a Kaplan-Meier survival analysis, the one-year, three-year, and five-year overall survival (OS) was 93.7, 84.0, and 73.9%, respectively, and the event-free survival (EFS) was 90.5, 79.2, and 67.5%, respectively. (2) The independent risk factors influencing prognosis in pediatric patients with HB were alpha-fetoprotein (AFP) < 100 ng/ml or > 1000 ng/ml (HR = 3.341, P = 0.005); platelet count > 400 x 109/L (pooled hazard ratio [HR] = 2.123, P = 0.026); PRETEXT stage IV (HR = 4.026, P = 0.001); vascular involvement (HR = 2.178, P = 0.019); distant metastasis (HR = 2.634, P = 0.010);and multifocality (HR = 2.215, P = 0.012). (3) A new risk-stratification system was established and divided into three groups: low risk, moderate risk, and high risk. There were statistical differences among the three groups (P = 0.002). Compared with the previous risk-staging systems, there was no significant difference in the survival rate. Although the effect in the guiding therapy was the same, the area under the curve for the ROC curve was 0.835 (95% CI: 0.784-0.885) for the new stratification system. Conclusion: This new risk-stratification system had a better predictive value for the prognosis of pediatric patients with HB than other stratification systems.