Polyphenylene　sulfide　(PPS),　commonly　used　as　a　core　material　for　high-temperature　flue　gas　treatment,　exhibits　elevated　viscosity　when　processed　even　at　temperature　exceeding　280　°C.　In　this　study,　a　novel　high-flowability　PPS-based　composite　was　fabricated　through　the　incorporation　of　graphitic　carbon　nitride　(g-C3N4)　via　a　well-established　melt　extrusion　procedure.　The　enhancement　of　flowability　in　PPS　was　verified,　and　the　material＇s　texture　structures　and　fundamental　properties　of　composites　with　varying　contents　were　determined.　The　composites　exhibit　well-dispersed　g-C3N4,　a　significant　reduction　in　shear　viscosity　(＞10　%),　a　notable　increase　in　melt　index　(＞30　%),　improved　crystallinity,　and　comparable　or　superior　performance　compared　to　pure　PPS.　When　the　g-C3N4　was　introduced　into　the　PPS　matrix,　a　phase-separated　composite　structure　was　formed.　This　structure　reduces　the　entanglement　degree　between　the　PPS　molecular　chains　and　provides　more　space　for　free-movement　of　the　PPS　chains,　and　thus　the　improvement　in　flowability　for　the　composites　can　be　clearly　demonstrated.　Therefore,　g-C3N4　can　be　used　as　a　novel　flow　modifier　to　enhance　the　flowability　and　stability　of　PPS　resin　without　compromising　its　fundamental　properties,　which　offers　significant　prospects　for　improving　productivity,　optimizing　energy　usage,　and　managing　costs　for　PPS-based　products.　©　2024　Elsevier　Ltd