Internet addiction (IA) and anxiety frequently co-occur in adolescence, but the characteristics of these associations, particularly the bidirectional symptom-level dynamics and patterns across genders, remain insufficiently explored. This study aimed to explore longitudinal interactions between IA and three anxiety subtypes (i.e., generalized anxiety, social phobia, and school phobia) among Chinese adolescents, while focusing on gender-specific patterns. The sample included 3,002 ninth-grade students (47.9% girls at T1; Mage = 14.60). Data were collected at two time points at six-month intervals. Cross-lagged panel network analysis was employed to investigate the longitudinal associations between IA and anxiety subtypes. The results revealed that the symptom "preoccupied with the internet" was the most influential node across overall and gender-specific networks. Gender-specific bridge symptoms emerged: "social phobia" in boys and "school phobia" in girls bridged IA and anxiety subtypes. Additionally, negative predictive pathways were identified in the boys' network, yet none were observed in the girls' network. These findings underscore the central role of cognitive preoccupation in comorbidity networks and highlight the gender-specific mechanisms linking anxiety and internet use. Targeting key transdiagnostic and bridge symptoms, especially school-related anxiety in girls and interpersonal avoidance in boys, can enhance tailored prevention and intervention strategies for anxiety occurring as a comorbidity in adolescents.