Copy number alteration (CNA) is a significant genetic change in pediatric B-cell acute lymphoblastic leukemia (B-ALL), with deletions, deletions, and deletions being the most common. Recent studies have increasingly highlighted the potential prognostic significance of these gene deletions and multiple co-deletions in pediatric B-ALL. This paper reviews the main detection methods for CNA, as well as the prognostic characteristics and treatment approaches for common CNA in pediatric B-ALL.