REDD+ (Reducing Emissions from Deforestation and Forest Degradation) and OECMs (Other Effective area-based Conservation Measures) serve as core tools in global ecological governance, with their primary objectives focused on carbon sequestration gains and biodiversity conservation, respectively. This paper systematically analyzes the conceptual conflicts and synergistic foundations between REDD+ and OECMs within biodiversity conservation efforts. It aims to reveal the strategic trade-off mechanisms of REDD+ and OECMs in multi-level governance. Innovatively, the paper proposes a "Carbon-Biodiversity" composite indicator system, providing a scientific pathway for cross-convention synergy within the international community and advancing the formation of a global ecological governance system integration paradigm.