University student academic competitions can test students' learning outcomes, improve their academic performance and stimulate their interest in learning. Exploring the behavioural mechanisms influencing students' academic competition is quite important, but there is currently little research on this topic. This study aims to fill this gap in the literature. We collected data from 460 university students during the fall semester of the 2023-2024 academic year and conducted a path analysis using structural equation modelling (SEM) to explore these behavioural mechanisms. The study found that external support, perceived value and institutional trust are significantly positively correlated with competition behaviour. However, the relationship between perceived usefulness and competition behaviour is not significant. Institutional trust plays a partial mediating role in the effects of external support, perceived usefulness and perceived value on competition behaviour. Therefore, the factors that affect college students' competitive behaviour include internal and external factors. The contribution of this research is to provide empirical evidence and explain what factors may affect competition behaviour.