Purpose: This study investigates the interplay among curriculum internationalization, service learning, intercultural communication skills, institutional support, and teachers' cross-cultural competence. It specifically assesses how curriculum internationalization and service learning impact teachers' cross-cultural competence, with a focus on the mediating effect of intercultural communication skills and the moderating influence of institutional support. A qualitative methodology was utilized, involving 24 semi-structured interviews with secondary school teachers in China. Thematic analysis was performed in three phases to uncover patterns and themes pertinent to the research objectives. Data collection continued until saturation was achieved, ensuring comprehensive and insightful findings. Findings: The findings indicate substantial relationships among curriculum internationalization, service learning, intercultural communication skills, institutional support, and teachers' cross-cultural competence. Both curriculum internationalization and service learning were found to have a positive effect on teachers' cross-cultural competence, with intercultural communication skills serving as a mediating factor in these relationships. Furthermore, institutional support was recognized as a critical moderating variable that enhances the development and application of intercultural communication skills among teachers. Implications/Originality: This study enriches the literature by elucidating the intricate dynamics between educational practices and teachers' cross-cultural competence. The results offer valuable implications for educational practice and policy, guiding the creation of interventions and strategies designed to enhance intercultural competence among both teachers and students. Furthermore, the research underscores the critical role of institutional support in cultivating inclusive learning environments that embrace and respect cultural diversity.