A comparative study of foreign environmental codes is beneficial for the advancement of environmental law codification in China. Among the approaches of formal codification and substantive codification, China’s Eco-Environmental Code should adopt a moderate codification approach as its guiding orientation. This approach should be driven by the systematic benefits of codification and aim to achieve the certainty, stability, and openness of the Code. The certainty dimension requires a clear definition of the scope of the Code, comprehensively incorporating delimiting criteria from comparative law and a detailed analysis of the legal attribution of special environmental norms. In contrast to the logical structures generally followed by foreign environmental codes, the stability of China’s Eco-Environmental Code depends on the abstract formulation of general provisions and the logical arrangement of specific provisions. Moreover, the proposed Code must also maintain a certain degree of openness to the external sources of environmental law to facilitate its renewal and evolution, addressing its relationship with specific environmental laws in response to the challenges of de-codification, and integrating with other legal branches to foster overall legal synergy.