Deepening regional cooperation between China and ASEAN urgently requires innovative paradigms for intercultural communication competence. This study focuses on the implications of the Confucian concept of “harmony without uniformity” for constructing a China-ASEAN-specific theoretical framework of intercultural communication. By reinterpreting classical texts and reconstructing the philosophical meaning of this concept, the study reveals its core value: the dynamic unity of embracing differences while fostering consensus. The current dominant Western paradigms guiding China-ASEAN intercultural communication practices exhibit structural limitations in both respecting cultural heterogeneity and seeking common values. The concept of “harmony without uniformity” thus offers a valuable indigenous theoretical resource. It suggests a shift from mere transplantation of foreign models to the development of a more inclusive and effective theoretical framework centered on cultural symbiosis. This new framework advocates for constructive dialogue to identify shared interests and cooperative opportunities, while fully acknowledging and respecting cultural diversity, thereby achieving harmonious coexistence and mutual development. Based on these insights, the study proposes practical pathways for theoretical transformation, including reshaping intercultural education concepts, enhancing adaptability in multicultural contexts, and strengthening policy coordination. The goal is to provide theoretical support and practical guidance for the steady and long-term development of China-ASEAN relations.