In　this　study,　heterostructured　copper　films　containing　different　proportions　of　highly　(220)-oriented　vertical　nanotwins　were　prepared　by　direct　current　(DC)　electroplating.　Uniaxial　tensile　tests　showed　that　the　mechanical　properties　improved　notably　when　the　volume　ratio　of　the　vertical　nanotwins　increased-the　film　with　the　88%　vertical　twins　exhibited　the　ultimate　tensile　strength　of　455　MPa,　approximately　83%　higher　than　those　of　the　equiaxed　Cu　films.　Postmortem　electron　microscopy　characterizations,　assisted　by　molecular　dynamics　simulations,　revealed　that　these　special　heterostructures　of　the　equiaxed　grains　and　vertical　nanotwins　facilitated　the　activation　of　multi-mode　slip　systems.　The　activation　of　multi-mode　slip　systems　leads　to　higher　dislocation　density,　thus　endowing　the　material　with　enhanced　mechanical　strength　and　work　hardening　rate　without　significant　loss　of　ductility.