To explore the mediating effect of mobile phone dependence between "weight anxiety" and depressive symptoms among adolescents, so as to provide a basis for the management of adolescent mental health. Electronic questionnaires were distributed in 12 schools from November 2021 to March 2022 using the multi-stage stratified cluster random sampling method. A total of 9225 adolescents finished the survey which included general questionnaire, “Weight Anxiety” Questionnaire, Self-rating Questionnaire for Adolescent Problematic Mobile Phone Use, and the Center for Epidemiological Studies Depression Scale (CES-D10). The results showed that β=0.39, P<0.001). Mobile phone dependence mediated the relationship between different manifestations of "weight anxiety" and depressive symptoms, with indirect effects of 13.66%, 14.58% and 22.04%, respectively. In conclusion, mobile phone dependence mediated the association between "weight anxiety" and depressive symptoms among adolescents. Individuals who are highly conscious of and sensitive to their body weight will make this indirect effect more significant.