To　overcome　the　strength-ductility　trade-off　dilemma,　the　microstructure　of　Al-Zn-Mg-Cu　alloy　was　controlled　by　adding　TiN　nanoparticles　and　heat　treatment　successively.　Al-Zn-Mg-Cu　alloy　deposition　with　both　high　strength　and　high　elongation　was　achieved.　The　tensile　strength,　elongation,　and　microhardness　were　increased　by　122.3%,　173.9%,　86.1%,　and　82.5%,　respectively.　The　columnar　grains　were　completely　transformed　into　equiaxed　grains　with　the　addition　of　TiN　particles　and　the　grain　size　was　reduced　by　92.9%.　The　elongation　increase　was　mainly　because　of　the　grain　refinement,　and　the　distribution　fluctuation　of　the　properties　decreased.　After　T6　heat　treatment,　the　elongation　remained　high　because　the　grain　size　changed　negligibly.　Precipitation　strengthening　is　the　main　mechanism　for　the　improved　tensile　strength　and　hardness.