This　work　systematically　investigates　the　thermal　deformation　behavior,　microstructural　evolution　involving　LPSO　phases,　and　strengthening　mechanisms　of　the　Mg-9Gd-2Er-0.5Zn　alloy　under　conditions　of　648-773　K　and　0.001-1　s-1.　The　results　show　that,　under　low　Z　conditions,　non-basal　slip　shears　grain　boundary　(GBs)　blocky　LPSO　(B-LPSO)　phases　into　smaller　blocks,　enhancing　dynamic　recrystallization　(DRX)　via　particle-stimulated　nucleation　mechanism.　Moderate　Z　conditions　feature　coexisting　intragranular　lamellar　LPSO　(L-LPSO)　and　GB　B-LPSO　phases:　L-LPSO　inhibits　DRX　and　basal　slip　activating,　while　B-LPSO　promotes　DRX,　yielding　a　bimodal　microstructure.　High　Z　conditions　induce　severe　stress　concentration　at　GB　B-LPSO　networks,　reducing　ductility.　The　extruded　Mg-9Gd-2Er-0.5Zn　alloy　achieves　a　UTS　of　397　MPa,　YS　of　360　MPa,　and　El　of　12.5　%,　with　strengthening　mechanisms　further　analyzed.