BACKGROUND: With the widespread use of smartphones, mobile phone addiction is becoming increasingly common among college students, which has a negative impact on their learning. This study aims to explore how mobile phone addiction leads to college students' learning burnout, with a focus on the mediating role of depression and the moderating role of FOMO (Fear of Missing Out). METHODS: Convenient sampling was used to collect 1862 valid questionnaires from over 10 universities in China. A moderated mediation model was constructed to analyze the relationship and mechanism among mobile phone addiction, learning burnout, depression and FOMO through structural equation modeling. RESULTS: (1) Mobile phone addiction has a significant positive impact on college students' learning burnout (β=0.4767, p < 0.001); (2) Depression plays a partial mediating role between mobile phone addiction and learning burnout (95% CI= [0.0706,0.1145]), with the mediating effect accounting for 19.34% of the total effect; (3) FOMO moderates the relationship between depression and learning burnout. Specifically, depression has a stronger impact on learning burnout among college students with low FOMO. CONCLUSION: This study reveals the mechanism of mobile phone addiction on college students' learning burnout, and confirms the mediating role of depression and the moderating role of FOMO. By integrating Self-Determination Theory, we further explain the specific mechanisms of FOMO's moderating role. This offers a which provides a new perspective for understanding the impact of mobile phone addiction on college students' learning burnout. It also provides a theoretical basis for colleges and universities to carry out mental health education and intervention.