Based on the dialogue with the traditional theories, this study investigates the development of related theories and explores the issue of the inadequate explanatory power of these traditional theories when applied to social reality. In Cosmopolitan Theory, the tension between cosmopolitanism and nationalism, universalism and pluralism, localism and globalism can never be properly dealt with. Community Theory confronts the contradiction between freedom and certainty and cannot achieve the basic goals of human pursuit of community.  With the significant enhancement of China's overall national strength, new cosmopolitanism is a beneficial approach and practice in the globalization of Chinese discourse. New cosmopolitanism inherits from cosmopolitanism its recognition of ″otherness″ and the pursuit of universalism, and turns from emphasizing consensus to acknowledgment, which embodies the good desire to achieve the greatest common divisor. Meanwhile, it promotes the ideas of ″harmony without uniformity″, ″harmony as fundamentality″, ″the doctrine of the mean″ and ″Great Unity″, and guides the ″harmony″ culture from instrumentality to publicity, which reflects the human-oriented way of thinking. In addition, new cosmopolitanism combines the theoretical development and the practical evolution of the community concept, as well as the recent practice of building a community with a shared future for humankind, and proposes more instructional and operational suggestions. New cosmopolitanism advocates a world of co-construction，which has resolved the issue of the relationship between China and the world. The idea of a community with a shared future for humankind softens the contradiction between freedom and certainty, and aims to establish a community with long-term stable ties on a global scale. At the same time, new cosmopolitanism advocates the construction of cross-cultural norms through communication and dialogue in the process of continuous learning and interaction, in order to coordinate the relationships between locality and globality and between universality and peculiarity. Compared with traditional theories, new cosmopolitanism transcends communicative rationality and ideology and makes the realization of the ultimate goals possible, which makes it applicable to the whole world. More importantly, new cosmopolitanism is operable and sustainable, fundamentally solving the problem of lacking a dynamic mechanism, which cosmopolitanism cannot solve. The practical path of new cosmopolitanism includes shaping the national image of a peaceful rise country, deepening strategic mutual trust among neighboring countries, strengthening economic cooperation with different countries, constructing a multi-dimensional communication system, respecting the existing international cooperation mechanism, innovating the organization mode of regional cooperation, expanding the demonstration effect of the “Belt and Road” initiative, and building a win-win global cooperation network. The study of the new cosmopolitanism theory plays an active role in refining the basic theoretical framework of international communication. Meanwhile, the study of its practical path has important real-world implications for enriching the global communication practice of Chinese discourse. New cosmopolitanism will have a positive impact on global communication, dialogue, cooperation and development. It will help to further enhance China's discourse system and promote the exchanges and interactions between China and the rest of the world.