<p>Academic buoyancy plays a critical role in high school mathematics learning; however, the factors influencing its development remain under-explored. Drawing on the onion model, this study investigates the relationships between students’ perceived peer interaction and academic buoyancy, with a particular focus on the mediating role of learning approaches. The sample consisted of 861 Chinese tenth-grade students. Structural equation modelling results revealed that perceived peer competition was negatively associated with deep learning approaches and academic buoyancy, while positively associated with surface learning approaches. Perceived peer cooperation was positively linked to deep learning approaches and negatively linked to surface learning approaches, but showed no significant relationship with academic buoyancy. Moreover, deep learning approaches were positively associated with academic buoyancy, whereas surface learning approaches were negatively associated. Bootstrap analysis further confirmed the mediating roles of learning approaches in the relationship between perceived peer interaction and academic buoyancy. Findings were interpreted through a sociocultural lens, and their practical implications were discussed.</p>