The emergence of new social media platforms has significantly influenced adolescent mental health through their engagement in selfie-related behaviours. This paper uses xiaohongshu as a research platform to explore the impact of users’ selfie-related behaviour on their body satisfaction and self-identity on social media. This study employed a questionnaire-based survey to examine 60 xiaohongshu users, aged 19-59, utilizing the selfie-posting frequency scale, self-viewing scale, verbal commentary on physical appearance Scale, body Image states scale, and body surveillance subscale. The results show that selfie editing and posting, selfie viewing, and positive appearance-related commentary positively affect body satisfaction, while negative appearance-related commentary negatively affect body satisfaction. There is no statistically significant association identified between body satisfaction and self-objectification. Adolescents’ psychological issues are influenced, in part, by their selfie-related activities within social networking environments. However, a mindful and rational engagement with these platforms can foster self-identity and contribute to the positive development of youth mental health.