The　national　independent　innovation　demonstration　zone(NIIDZ)is　an　independent　innovation　policy　that　plays　a　crucial　role　in　implementing　strategies.Given　the　importance　of　the　NIIDZ,this　study　uses　panel　data　of　278　prefecture-level　cities　in　China　from　2006　to　2020　and　empirically　examines　the　effect　and　internal　mechanism　of　the　NIIDZ　on　green　economic　efficiency(GEE)using　the　difference-in-difference　model(DID).The　results　show　that　the　NIIDZ　effectively　enhances　the　growth　of　GEE,and　the　results　remain　valid　through　several　robustness　tests,such　as　year-by-year　propensity　score　matching.The　transmission　mechanism　sug-gests　that　the　NIIDZ　indirectly　drives　GEE　by　accelerating　scientific　and　technological　investment,promoting　talent　concentration,and　optimizing　the　industrial　structure.Moreover,heterogeneity　analysis　reveals　that　the　promotion　effect　of　the　NIIDZ　on　GEE　is　more　prominent　in　the　eastern　region　and　high　green　development　level　areas.The　study＇s　findings　can　serve　as　a　reference　for　China　to　further　utilize　the　policy　effectiveness　of　the　NIIDZ　and　accelerate　the　high-quality　development　of　the　green　economy　in　the　future.