This study evaluates the policy effectiveness of Marine Protected Areas (MPAs) in advancing the blue economy, using a multidimensional framework integrating ecological conservation, economic development, and social equity. Based on panel data from 50 MPAs across 15 countries (2018–2023), we employ mixed-methods research (quantitative regression and qualitative case studies) to identify key policy drivers and bottlenecks. Results show that MPAs with adaptive management mechanisms and stakeholder participation achieve 32% higher ecological restoration rates and 27% greater local fishery income growth than traditional MPAs. However, 45% of MPAs face funding shortages and weak law enforcement, limiting their blue economy contributions. This paper provides policy recommendations for optimizing MPA governance to balance conservation and development.