Objective To explore the influencing factors of self-stigma in adolescents with mood disorders and the chain mediating role of self-esteem and depression symptoms between childhood trauma and self-stigma. Methods Convenience sampling was used to select 220 adolescents with mood disorders at Wuhu Hospital of Beijing Anding Hospital affiliated with Capital Medical University from November 2022 to November 2023 for the study. Internalized Stigma of Mental Illness Scale （ISMI）， Beck Depression Inventory （BDI）， Rosenberg Self-Esteem Scale （RSES）， and Childhood Trauma Questionnaire-Short Form （CTQ-SF） were used to assess patients' self-stigma， depressive symptoms， self-esteem， and childhood trauma. Multiple linear regression was used to analyze the factors influencing self-stigma in adolescents with mood disorders， and Pearson correlation was used to analyze the correlation between self-stigma， depressive symptoms， self-esteem， and childhood trauma. Mediating effects were tested using the Model6 of the SPSS PROCESS macro program. Results A total of 220 questionnaires were sent out in this study, and 204 were effectively collected, with an effective recovery rate of 92.7%. According to the diagnostic criteria of ICD-10， the patients were classified into the depression disorder group （n=126） and the depressive episode of bipolar disorder group （n=78）. ISMI， BDI， RSES and CTQ-SF scores of 204 adolescents with mood disorders were （74.44±14.45）， （20.08±8.54）， （20.62±5.34）， （57.02±14.88）， respectively. The patients' ISMI total scores were positively correlated with their BDI total scores and CTQ-SF total scores， and the differences were statistically significant （r=0.741，0.573； all P＜ 0.01）. RSES total score showed a statistically significant negative correlation with the ISMI total score， BDI total score， and CTQ-SF total score （r=-0.759，-0.755， and -0.491； all P＜ 0.01）. In the group of adolescents with depressive disorders， self-esteem and depressive symptoms played a chain-mediating role between childhood trauma and self-stigma， with a mediating effect value of 0.27， which accounted for 55% of the total effect size. In the group of adolescents with depressive episodes of bipolar disorder， childhood trauma did not directly predict self-stigma ［direct effect=0.15， 95%CI （-0.03， 0.32）］， and the mediating effect was only statistically significant for one pathway： childhood trauma → self-esteem → self-stigma ［indirect effect=0.33， 95%CI （0.17， 0.51）］. Conclusions Frequency of hospitalization， duration of disease， severity of depressive symptoms， childhood trauma， and self-esteem are associated with self-stigma in adolescents with mood disorders. Childhood trauma in adolescents with depressive disorders can affect self-stigma directly or indirectly through the chain-mediating effects of self-esteem and depressive disorder. Childhood trauma in adolescents with depressive episodes of bipolar disorder can affect self-stigma only through the mediating role of self-esteem.