Collaborative　industrial　agglomeration　has　an　important　supporting　role　in　improving　the　efficiency　of　regional　green　development.　This　paper　examines　the　spatial　spillover　effects　and　mechanisms　of　industrial　agglomeration　on　regional　green　development　efficiency,　from　a　spatial　perspective.　The　research　results　show　that:　industrial　synergistic　agglomeration　has　a　positive　role　in　promoting　regional　green　development,　and　has　spatial　agglomeration　and　spatial　spillover　effects.　The　level　of　green　technological　progress　plays　a　more　prominent　role　as　a　mediating　effect　in　this　process.　The　results　of　regional　heterogeneity　show　that　the　impact　of　synergistic　industrial　agglomeration　on　the　improvement　of　green　development　efficiency　is　higher　in　the　central　and　western　regions　than　in　the　eastern　regions.　This　paper　demonstrates　the　guiding　role　of　productive　services　and　manufacturing　industries　in　green　development,　providing　theoretical　guidance　for　further　institutional　dividends　in　China＇s　green　development,　and　thus　improving　the　level　of　regional　green　development.　©　2022　Elsevier　B.V.