Green　development　is　an　inherent　requirement　for　effectively　responding　to　severe　resource　and　environmental　problems　and　adapting　to　major　economic　and　social　problems.　Based　on　the　panel　data　of　272　prefecture-level　cities　in　China　from　2011　to　2018,　this　paper　takes　the　next-generation　Internet　model　city　policy　as　a　quasi-natural　experiment　for　the　first　time,　and　uses　the　DID　model　to　empirically　test　the　impact　and　mechanism　of　the　next-generation　Internet　model　city　construction　on　green　total　factor　productivity　(GTFP).　The　results　show　that　the　next-generation　Internet　demonstration　city　has　a　significant　role　in　promoting　GTFP,　and　after　being　rated　as　a　next-generation　Internet　demonstration　city,　its　GTFP　has　increased　by　about　6.3%.　This　conclusion　is　still　valid　after　a　series　of　robustness　tests,　From　the　mechanism　analysis,　it　is　concluded　that　the　next-generation　Internet　demonstration　cities　mainly　promote　GTFP　through　industrial　structure　optimization　and　technological　innovation.　A　further　test　of　heterogeneity　shows　that　the　construction　of　next-generation　Internet　demonstration　cities　is　more　significant　in　promoting　GTFP　in　large-scale　cities　and　resource-based　cities.　The　research　in　this　article　provides　a　wealth　of　empirical　evidence　for　the　implementation　of　my　country＇s　next-generation　Internet　model　city　policies.