Background <p>Athlete burnout, characterized by emotional and physical exhaustion, reduced accomplishment, and devaluation of sport, is a growing concern in sports psychology. Life stress has been identified as a significant factor associated with athlete burnout, yet the underlying mechanisms remain unclear. This study explores the relationship between life stress and athlete burnout, with a focus on the chain mediation roles of mindfulness and cognitive emotion regulation strategies.</p> Methods <p>A total of 453 athletes from China were surveyed using convenience sampling. Participants completed four questionnaires: the College Student-Athletes’ Life Stress Scale, Five Facet Mindfulness Questionnaire, Cognitive Emotion Regulation Questionnaire, and Athlete Burnout Questionnaire. Data were analyzed using SPSS 22.0 for descriptive statistics and Amos 24.0 for structural equation modeling to explore mediating effects.</p> Results <p>Life stress was positively correlated with athlete burnout. Cognitive emotion regulation strategies were a significant mediator in this relationship. A chain mediation effect was found, where mindfulness influenced cognitive emotion regulation, which in turn reduced athlete burnout.</p> Conclusion <p>Life stress is significantly associated with athlete burnout, and cognitive emotion regulation strategies play a crucial role in mitigating this effect. Interventions to reduce burnout should emphasize improving cognitive emotion regulation, potentially through mindfulness training.</p>