Based on the historical position of the "new era" and "changes unseen in a century", Xi Jinping Thought on the Rule of Law and Ecological Civilization has profoundly answered a series of major questions in the process of comprehensively promoting the rule of law and the construction of ecological civilization. It is a theoretical system with profound connotation, rigorous logic, scientific ideas and broad vision. First of all, the theoretical construction of Xi Jinping Thought on the Rule of Law and Ecological Civilization is self-sufficient. On the theoretical innovation level, Xi has absorbed the essence of traditional culture represented by "Confucianism, Buddhism and Taoism" culture and developed the Marxist view of ecological philosophy and rule of law. In the aspect of problem solving, the current "four major deficits" crisis has been solved and the Chinese plan has been put forward with the green development concept of harmonious coexistence between man and nature and the global governance concept of extensive consultation, joint contribution and shared benefits as the core. In the global perspective, the concept of "a community with a shared future for mankind" is constructed and the future global ethics are put forward. Secondly, the functional expression of Xi Jinping Thought on the Rule of Law and Ecological Civilization is mutually supportive:they guide each other in values and support each other in methodology, and jointly promote the modernization of national governance system and governance capacity. Finally, the environmental code not only carries out the governance thought of Xi Jinping Thought on the Rule of Law under the formal rational observation, but also ensures the steady progress of ecological civilization construction by using the rule of law thinking and means. At the same time, Xi Jinping Thought on Ecological Civilization has been implemented at the level of essential rationality, and an ecological civilization system has been constructed with systematic and holistic methods and the concept of "life community". It not only realizes the systematicness of form and appearance, the openness of structure and content, and the self-appropriateness of logical connection of the environmental code through moderate codification, but also realizes the rationality of system arrangement, the fluency of procedure operation and the stability of legal system through the legislative technical support of "general provisions + specific provisions". Therefore, the environmental code is the best embodiment of Xi Jinping Thought on the Rule of Law and Ecological Civilization.