Introduction" Previous research has found that family factors predict adolescents' academic burnout, but few studies have described the mechanisms underlying the relationship. At the same time, there is a lack of longitudinal data on the possible mechanisms. This study aimed to examine the relationship between family functioning and academic burnout and the serial mediating effect of future time perspective and emotional problems (measured by depression and anxiety). Methods: Between 2022 and 2023, a total of 504 Chinese adolescents (M[subscript age] = 16.18, SD = 0.70, 59.13% females at Time 1) participated in a two-wave longitudinal study with a 10-month interval. The longitudinal path analysis (family functioning at Time 1[right arrow]future time perspective at Time 2[right arrow]emotional problems at Time 2[right arrow]academic burnout at Time 2) and cross-lagged panel model (CLPM) were used to verify the longitudinal mediating relationship. Results: Family functioning was negatively correlated with adolescent academic burnout and emotional problems, and positively correlated with future time perspective at both time points. Both longitudinal path analysis and CLPM analysis supported a longitudinal serial mediation, showing that the effect of family functioning on academic burnout was mediated by future time perspective and emotional problems. Conclusions: This study provided longitudinal evidence for a cognitive-emotional pathway linking family functioning to academic burnout. By identifying future time perspective and emotional problems as mediators, the findings highlighted the importance of addressing family factors, future time perspective, and emotional problems in interventions aimed at reducing academic burnout among adolescents.