Abstract: The prominent concept of harmonious coexistence between humanity and nature holds a pivotal position within Xi Jinping's Thought on Ecological Civilization, with deep integration observed in core ideologies, intellectual trajectories, and pathways to modernization. From a theoretical construction standpoint, within Xi Jinping's Thought on Ecological Civilization, the significant principle of harmonious coexistence between humanity and nature abides by the materialist principle of seeking truth from facts, and advocates a systematic and holistic dialectical approach. The concept applies the method of contradiction analysis to resolve the tension between ecological benefits and economic benefits, highlights the spirit of the theory of practice, adheres to the developmental laws of historical materialism, and stimulates the subjective initiative of the entire society to construct a harmonious ecological environment. On the practical path, it is essential to maintain consistency among conceptual guidance, institutional guarantees, and practical implementation. This can be achieved by fostering a societal consensus on ecological civilization, refining legal and policy frameworks and regulatory mechanisms, promoting the green transformation of the economy and society, and thereby realizing harmonious coexistence between humanity and nature.