China takes the construction of ecological civilization as a national strategy for sustainable development. Over the past decade, China has made remarkable achievements in the construction of ecological civilization. Xi Jinping Thought on Ecological Civilization is the guide for China’s ecological civilization practice. It shows that China is not only committed to the preservation and restoration of the natural resources and environment, but also attaches importance to social equity and people’s well-being, not only committed to improving the relationship between humanity and nature, but also focuses on improving the relationship among people. Both Chinese traditional culture and Marxist materialist dialectics hold that all things are interconnected, reflecting a relational way of thinking in China. China’s vision of the world is also a product of such relational thinking. The Community with a Shared Future for Humanity and the Belt and Road Initiative proposed by China are full of relational thinking. This makes a significant difference between China’s diplomacy and the Western individualist, mechanical thinking-dominated international relations theory, and diplomatic practice based on power politics. China’s propositions in international relations and diplomatic practice reflect the characteristics of connectivity politics based on relational thinking. Due to differences in philosophy, China and the West have different world visions and ways of dealing with things. The relational world view is the root of China’s construction of ecological civilization and its approach in handling international affairs.