Objective: Introducing resilience into this study to investigate the mediating role of self-esteem in the peer relationships and mental health of the orphans in Sichuan Earthquake. Methods: 401 children including the orphans in Sichuan Earthquake and three control groups were surveyed with questionnaires including Self-esteem Scale and Peer Nomination Questionnaire and Chinese Mental Health Inventory. Results: There was significant group difference in Self-esteem, and the Rizhao control group had higher score than the other groups. The orphans in earthquake had more peer acceptance than the other groups. There was no difference between children in Sichuan and Rizhao. The mental health and peer relationships were mediated by self-esteem of the orphans in earthquake, who paid more attention to peer acceptance to influence self-denial that had a negative connection with mental health. Conclusion: The important effect of self-esteem in peer relationships and mental health was supported by SEM in this study.