PURPOSE: High levels of depression are common among men who have sex with men (MSM) in China, and there is limited research on the relationship between MSM stigma and depression. Guided by the psychological mediation framework, to explore the relationship between stigma and depression among MSM and how positive sexual identity plays a role in it, we tested this model whether: 1) enacted MSM stigma, perceived MSM stigma, and positive sexual identity are associated with depression; 2) their effects on depression are mediated through resilient coping and social support; and 3) perceived MSM stigma is a mediator of the effects of enacted MSM stigma and positive sexual identity on depression. METHODS: We conducted mediation analyses using structural equation modeling (SEM) on data from a cross-sectional survey conducted among 1014 MSM recruited using a non-probability sampling method in December 2022. The data passed general analyses such as normality and correlation, which allowed for modeling. The final SEM fit metrics indicated that the model was acceptable. RESULTS: Structural equation modeling results showed that enacted stigma directly and positively affected depressive symptoms (β = 0.558, 95 % confidence interval = 0.457 ～ 0.644, P < 0.001). Perceived stigma had a positive effect on depressive symptoms (β = 0.114, 95 %CI = 0.036 ～ 0.200, P = 0.002). Positive identity had a positive effect on depressive symptoms (β = 0.086, 95 %CI = 0.016 ～ 0.162, P = 0.013). In addition, the results of mediation effect analysis showed that the indirect effect of enacted stigma on the effect of depression through social support was (β = 0.040, 95 %CI = 0.003 ∼ 0.017, P = 0.049); The indirect effect of perceived stigma on the effect of depression through resilient coping was (β = -0.015, 95 %CI = -0.034 ∼ -0.002, P = 0.056); The indirect effects of positive sexual identity on the effect of depression through resilient coping and social support were (β = -0.025, 95 %CI = -0.056 ∼ -0.002, P = 0.052) and (β = -0.056, 95 %CI = -0.101 ∼ -0.023, P = 0.005). CONCLUSION: Resilient coping and social support mediated the relationship between stigma and depression, and both were influenced by positive identity. This study reveals that enhancing coping and social support may reduce the impact of stigma on depressive symptoms, both of which are potential targets for interventions for MSM. Guiding MSM to develop a positive sexual identity is conducive to reducing the prevalence of depressive symptoms among MSM.