Nanocrystalline　(NC)　structure　can　lead　to　the　considerable　strengthening　of　metals　and　alloys.　Obtaining　appropriate　comprehensive　mechanical　properties　is　always　the　goal　of　metallic　materials.　Here,　a　nanostructured　Al-Zn-Mg-Cu-Zr-Sc　alloy　was　successfully　processed　by　high-pressure　torsion　(HPT)　followed　by　natural　aging.　The　microstructures　and　mechanical　properties　of　the　naturally　aged　HPT　alloy　were　analyzed.　The　results　show　that　the　naturally　aged　HPT　alloy　primarily　consists　of　nanoscale　grains　(similar　to　98.8　nm),　nano-sized　precipitates　(20-28　nm　in　size),　and　dislocations　(1.16　x　10(15)　m(-2)),　and　exhibits　a　high　tensile　strength　of　851　&　PLUSMN;　6　MPa　and　appropriate　elongation　of　6.8　&　PLUSMN;　0.2%.　In　addition,　the　multiple　strengthening　modes　that　were　activated　and　contributed　to　the　yield　strength　of　the　alloy　were　evaluated　according　to　grain　refinement　strengthening,　precipitation　strengthening,　and　dislocation　strengthening,　and　it　is　shown　that　grain　refinement　strengthening　and　precipitation　strengthening　are　the　main　strengthening　mechanisms.　The　results　of　this　study　provide　an　effective　pathway　for　achieving　the　optimal　strength-ductility　match　of　materials　and　guiding　the　subsequent　annealing　treatment.