How to interpret Xi Jinping Thought on Culture from a new angle is an important task of contemporary Marxist theoretical work. After a review of the current interpretation of many points of view, it is further pointed out that the researchers should stand at a higher station. To solve this problem, we need to define the theoretical concept of Xi Jinping Thought on Culture. Therefore, from the perspective of Marxist epistemology, it is defined as follows at the basic level: Xi Jinping Thought on Culture is the Chinese theory of the Communist Party of China in the global context, which systematically expounds the modern civilization of the Chinese nation in Chinese concepts. This definition reveals the essence of Xi Jinping Thought on Culture: Chinese theory, that is, a Chinese political-cultural theory based on Chinese historical and cultural experience and Chinese socialist practical experience in the world pattern of the new era. In terms of cultural form, Xi Jinping Thought on Culture covers the basic principles of Marxism and Chinese culture, and interprets new culture in terms of Chinese classical theory, thus forming a culture with Chinese national characteristics and new era characteristics. From the aspect of content, Xi Jinping Thought on Culture plans the development prospect of the modern civilization of the Chinese nation from the angle of cultural strategy, policy and so on, and creates an open civilization system of exchange and mutual learning for the Chinese nation, based on China and facing the world. Therefore, both the cultural form and the theoretical content constitute the basic meaning of the present Chinese theory. In this sense, Chinese theory is the keyword of Xi Jinping Thought on Culture, which indicates that Chinese culture has entered a new stage of development by leaps and bounds. It explains the innovation theoretical characteristics of Xi Jinping Thought on Culture and highlights the cultural strategic value of Xi Jinping Thought on Culture.