To explore the mediating effect of emotion regulation strategies on the correlation between parental emotion socialization and internalizing problems in adolescents, as well as the moderating effect of gender, a questionnaire survey was administered to 1078 junior high school students (Mage = 13.96 ± 1.00). The results revealed that supportive parental emotion socialization was negatively correlated with adolescents internalizing problems, whereas non-supportive parental emotion socialization was positively correlated with such problems. Cognitive reappraisal and expressive suppression strategies functioned as parallel mediators in the relationship between supportive parental emotion socialization and adolescent internalizing problems, while only expressive suppression mediated the correlation between non-supportive emotion socialization and adolescent internalizing problems. Gender did not exhibit a moderating effect on the mediation model. These findings suggest that supportive parental responses to adolescents' negative emotions can reduce the incidence of depression and anxiety by cultivating increased utilization of cognitive reappraisal strategies and decreased reliance on expressive suppression strategies among adolescents, whereas non-supportive responses exacerbate the occurrence of depression and anxiety by promoting greater utilization of expressive suppression strategies. In addition, no significant gender differences were observed in the mediation effects. These findings emphasize the importance of prevention programs focusing on parental emotion socialization in adolescence.