The　contradiction　between　mechanical　properties　and　thermal　conductivity　of　magnesium　alloys　is　a　roadblock　for　their　widespread　applications.　In　this　study,　we　developed　a　hot-extruded　Mg-8Gd-1Er-8Zn-1Mn　alloy　with　high-strength　and　high-thermal-conductivity　via　dual-phase,　W-phase　and　α-Mn,　synergistically　strengthening.　The　alloy　extruded　at　300°C　exhibited　the　yield　strength　and　elongation　of　372　MPa　and　12　%,　respectively,　it　simultaneously　demonstrated　a　high　thermal　conductivity　of　134.3W/(m·K).　After　extrusion,　the　original　coarse　W-phase　in　the　alloy　was　broken　into　near-spheroidal　particles,　which　reduced　the　probability　of　electron　scattering.　In　addition,　a　large　number　of　solute　atoms　dynamically　precipitated　in　the　form　of　nanoscale　rod-like　W-phase　and　α-Mn,　making　α-Mg　matrix　revert　to　a　nearly　periodic　arrangement　state.　The　high　yield　strength　of　the　alloy　is　predominantly　determined　by　grain　boundary　strengthening　as　well　as　W-phase　and　α-Mn　dual-phase　strengthening.　Notably,　the　strategy　of　dual-phase　strengthening　provides　a　valuable　approach　for　developing　structure-function　integrated　Mg　alloys.　©　2024