In　order　to　scientifically　and　reasonably　formulate　the　super-close　construction　and　reinforcement　scheme　of　urban　underground　engineering,　the　three-dimensional　impact　zoning　and　its　application　are　investigated　by　using　the　numerical　simulation　and　field　monitoring　based　on　the　New　Airport　Line　of　Beijing　Metro　super-close　to　and　overcrossing　the　existing　Line　10.　The　expressions　for　horizontal　and　vertical　impact　zoning　relying　on　the　project　are　deduced,　the　3D　impact　zoning　based　on　the　uplift　value　of　the　existing　tunnel　is　determined,　and　the　countermeasures　for　each　impact　zoning　are　put　forward.　Considering　the　construction　space　and　economic　indice,　the　reinforcement　measures　based　on　3D　impact　zoning　of　the　supporting　project　are　optimized.　Through　the　comparative　analysis　of　numerical　simulations,　it　can　be　seen　that　the　optimized　reinforcement　measures　of　retaining　wall　meet　the　construction　safety　requirements.　The　recommended　optimal　reinforcement　measures　of　retaining　wall　are　adopted　for　the　construction　of　the　supporting　project.　The　on-site　monitoring　data　show　that　the　construction　influence　laws　of　the　displacement　change　of　the　arch　crown　of　the　existing　tunnel　are　consistent　with　the　numerical　simulation　analysis,　and　the　displacement　values　are　less　than　the　control　standard,　indicating　that　the　proposed　3D　impact　zoning　and　reinforcement　measures　can　ensure　the　construction　safety　of　the　supporting　project.　The　research　results　may　provide　reference　for　the　construction　safety　control　of　similar　projects.　©　2023　Chinese　Society　of　Civil　Engineering.　All　rights　reserved.