Enhancing　the　specific　capacitance　and　rate　performance　of　graphene　based　fiber-shaped　super　capacitors　(FSSCs)　is　critical　to　achieving　advanced　energy　storage　devices　with　desired　performance.　Here,　hierarchically　porous　reduced　graphene　oxide/poly　(3,4-ethylenedioxythiophene):poly　(4-styrenesulfonate)　(rGO/PEDOT:PSS)　hybrid　fiber　was　constructed　by　co-assembling　confined　growth　and　acid　treatment　strategy.　The　rationally　designed　hybrid　fiber　addressed　the　issues　of　excellent　conductivity　and　abundant　porous　channels　for　fast　electrons　transfer　and　rapid　ions　diffusion.　As　indicated,　highly-oxidized　small-sized　GO　precursor　was　utilized　to　endow　rGO　fiber　with　abundant　ions　diffusion　channels　and　ions　adsorption　interfaces　for　double-layer　capacitance,　as　well　as　ample　oxygen　functional　groups　for　additional　pseudocapacitance.　The　incorporation　of　acid-treated　PEDOT:PSS　also　prevents　the　stacking　of　rGO　sheets,　improves　the　electrical　conductivity　and　provides　partial　capacitance.　Attributed　to　the　synergy,　the　obtained　hybrid　fiber　exhibits　remarkably　improved　performance　in　FSSC　with　volumetric/areal　specific　capacitance　of　226.5　F　cm(-3)/279.3　mF　cm(-2)　at　0.5　A　cm(-3)　and　rate　performance　of　74.7%　capacitance　retention　at　50　A　cm(-3),　which　is　much　superior　to　the　counterpart　of　previously-reported　FSSC　devices.　Meanwhile,　the　resultant　FSSC　device　also　exhibits　superb　electrochemical　stability　(91%,　10000　cycles),　holding　a　great　application　prospect　in　wearable　electronics.　(C)　2021　Elsevier　Ltd.　All　rights　reserved.