Objective To explore the impact mechanism of family functioning on the general quality of life of adolescents with anxiety， depression， and somatic symptoms， and analyze the chain-mediating effect of physical appearance and attributes， as well as anxiety， depression， and somatic symptoms in this relationship. Methods The cross-sectional study was conducted. Using convenience sampling， adolescents who visited the Department of Psychosomatic Medicine at Beijing Children's Hospital， Capital Medical University， between June 2024 and December 2025 were continuously enrolled as study subjects. Clinical assessments were conducted using the Family Assessment Device（ FAD）， Physical Appearance and Attribute Sub-Scale of Piers-Harris Children's Self-concept Scale， Screen for Child Anxiety Related Emotional Disorders（ SCARED）， Depression Self-Rating Scale for Children（ DSRSC）， Bodily Distress Syndrome（ BDS）， and Quality of Life Scale for Children and Adolescents（ QLSCA）. Based on the results of the normality test， Spearman rank correlation analysis was used to explore the relationships among the variables. After controlling for covariates such as gender and age， the PROCESS macro（ Model 6） was used to test for multiple chain-mediating effects. Results A total of 579 adolescents were included. The scores for the problem solving， communication， roles， affective responsiveness， affective involvement， behavior control， and general family functioning dimensions in FAD were 2.33（2.00，2.67），2.56（2.22，2.89），2.36（2.09，2.64），2.50（2.17，3.00），2.43（2.14，2.71），2.33（2.11，2.56）， and 2.33（ 2.00，2.75）， respectively. The score of the PHCSS Physical Appearance and Attribute Sub-Scale was 5.00（3.00，8.00）. The total scores of SCARED， DSRSC， BDS， and QLSCA self-satisfaction dimension were 38.00（ 20.00，54.00），20.00（ 13.00，25.00）， 34.00（ 17.00，51.00）， and 12.00（ 9.00，16.00）， respectively. There were statistically significant differences in the scores on the problem solving， communication， roles， affective responsiveness， affective involvement， behavioral control， and general family functioning dimensions of the FAD among patients of different genders（ all P ＜ 0.05）. There were no statistically significant differences in the scores for the aforementioned dimensions of FAD among the 12-， 13-， and 14-year-old age groups（ all P ＞ 0.05）. Correlation analysis showed that the total score of the general family functioning dimension in the FAD was negatively correlated with physical appearance and attributes， as well as QLSCA self-satisfaction dimension scores（ ρ=-0.442， -0.575； all P ＜ 0.001）， and positively correlated with SCARED， DSRSC， and BDS scores（ ρ=0.520， 0.605， 0.467； all P ＜ 0.001）， with statistically significant differences. The score for physical appearance and attributes was positively correlated with the QLSCA self-satisfaction dimension score（ ρ=0.599， P ＜ 0.001） and negatively correlated with the SCARED， DSRSC， and BDS scores（ ρ= -0.580， -0.639， and -0.474； all P＜ 0.001）， with these differences being statistically significant. SCARED， DSRSC， and BDS scores were positively correlated with each other（ ρ=0.754 to 0.819； all P ＜ 0.001）， and negatively correlated with QLSCA self-satisfaction dimension scores（ ρ=-0.805 to -0.690； all P＜0.001）， with statistically significant differences. The mediation analysis showed that a total of 21 chain-mediating pathways were significantly established with statistical differences（ P＜0.001）， The total indirect effects of the anxiety， depression， and somatic symptom models accounted for 55.0% to 87.6%， 66.8% to 92.4%， and 51.1% to 77.6% of the total effect, respectively. Conclusions The impairment of somatic self-awareness and the exacerbation of anxiety， depression， and somatic symptoms constitute the key psychopathological chain through which family dysfunction leads to a decline in adolescents' quality of life. In clinical interventions， in addition to managing superficial emotions and physical symptoms， there is an urgent need to implement systematic family therapy interventions（ especially optimizing family behavior control models） and to help adolescents rebuild a positive physical self-acceptance to fundamentally block pathological mechanisms and improve their quality of life.