<p>Guided by the Stress-Diathesis Model and Ecological Systems Theory, this study aimed to explore how environmental vulnerability profiles contribute to suicidal ideation among Chinese adolescents, focusing on the mediating roles of depression and anxiety. A survey of 2,616 adolescents in Guangdong Province assessed six environmental risk factors across family, school, and social domains: high academic pressure, low family intimacy, frequent family conflict, parental emotional instability, insufficient social support, and strained teacher-student relationships. Latent profile analysis identified distinct vulnerability profiles, and mediation analyses tested indirect effects via depression and anxiety. Four vulnerability profiles emerged: Low Risk group (38.1%), with minimal exposure to all risk factors; Moderate Risk group (36.3%), with moderate adversity across domains; Isolation but Conflict-Free group (18.9%), marked by low family intimacy and limited support but low conflict; and High Risk with Family Disturbance group (6.7%), characterized by pronounced family conflict and parental emotional instability. The fourth group showed the highest psychological distress and suicidal ideation, while the third also showed elevated suicide risk despite low conflict. Depression and anxiety significantly mediated associations between profiles and suicidal ideation. Findings highlight the need for ecologically informed suicide prevention strategies addressing both psychological symptoms and contextual stressors.</p>